What Is Vancouver Style?
Vancouver referencing style was established by the International Committee of Medical Journal Editors (ICMJE) following a 1978 meeting in Vancouver, British Columbia — hence the name. The resulting guidelines, known as the Uniform Requirements for Manuscripts Submitted to Biomedical Journals, standardised citation formatting for hundreds of medical and scientific journals worldwide.
Vancouver uses a sequential numbered system: every source is assigned a number in the order it is first cited in the text, and that number appears in superscript¹ or in square brackets [1] in the text. The full reference details appear at the end of the paper in a numbered list, ordered by first appearance — not alphabetically.
It is the citation standard for most journals published under the biomedical umbrella, including many listed in PubMed, MEDLINE, and the NLM (National Library of Medicine) catalog. NLM style is a closely related variant that uses the same numbering approach with minor formatting differences.
Which Disciplines Use Vancouver?
Vancouver is the citation standard expected in the following life and health science disciplines:
- Biology and Microbiology — molecular biology, genetics, cell biology, microbiology
- Medicine and Clinical Sciences — clinical research papers, systematic reviews, case reports
- Nursing and Midwifery — many nursing programmes require Vancouver for research assignments
- Pharmacology and Pharmacy — drug studies, pharmacokinetics, clinical trials
- Biochemistry and Biophysics — laboratory research, enzyme studies, structural biology
- Environmental Science — ecological research, epidemiological studies
- Public Health — population studies, health policy, epidemiology
Always check your department's specific guidelines — some biology and health science programmes use APA instead of Vancouver, particularly at undergraduate level.
Core Rules of Vancouver Style
- Number sources in the order they first appear in the text — not alphabetically
- In-text: superscript numbers¹ or numbers in brackets [1] — check your journal or institution
- Once a source has been assigned a number, always use the same number for subsequent citations of that source
- Multiple citations: [1,2] or [1–4] for a range
- Author names: Last name followed by initials without full stops — e.g. Chen JK (not J. K. Chen)
- List up to 6 authors, then add "et al." — e.g. Smith A, Jones B, Brown C, et al.
- Journal titles are abbreviated using standard NLM abbreviations
- No italics required in the reference list (unlike APA)
- Year;Volume(Issue):pages — semicolon after year, colon before pages
In-Text Citations
Vancouver in-text citations are superscript numbers placed immediately after the punctuation of the relevant sentence, or after the name of the author being cited. Some institutions and journals use square brackets instead of superscripts — both are acceptable variants of Vancouver; just be consistent throughout your document.
Superscript format
CRISPR-Cas9 editing has shown therapeutic promise in sickle cell disease.¹
This result has been replicated across multiple studies.²⁻⁴
As Chen et al.⁵ demonstrated, the binding affinity increases with temperature.
Square bracket format (equally valid)
CRISPR-Cas9 editing has shown therapeutic promise in sickle cell disease. [1]
This result has been replicated across multiple studies. [2-4]
As Chen et al. [5] demonstrated, the binding affinity increases with temperature.
Key rule on reuse: if you cite source [3] early in your paper and then refer to it again in your discussion, you still write [3] — you never assign a new number to a source already in the list. Only new sources get new numbers.
Journal Articles
Journal articles are the backbone of most biomedical reference lists. Use NLM abbreviations for journal names — these can be looked up via the NLM catalog at nlm.nih.gov.
Format
Author AA, Author BB, Author CC. Title of article. Journal Abbrev. Year;Volume(Issue):StartPage-EndPage.
Example — up to 6 authors
1. Chen JK, Patel RM, Torres LD. CRISPR-Cas9 off-target effects in human stem cells: a systematic review. Nat Biotechnol. 2023;41(4):512-525.
Example — more than 6 authors (truncate at 6 + "et al.")
2. Smith A, Jones B, Brown C, Wilson D, Taylor E, Johnson F, et al. Genome-wide association study of metabolic syndrome in diverse populations. Science. 2022;378(6621):890-901.
Example — with DOI (recommended when available)
3. Nguyen TH, Rahman AM, Park SY. Machine learning for early sepsis detection in ICU patients. Lancet Digit Health. 2023;5(7):e445-e453. doi:10.1016/S2589-7500(23)00089-5
Example — article number (no page range)
4. Liu Y, Zhang H. Gut microbiome composition and its relationship to metabolic disease. Cell Rep. 2023;42(8):112893.
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Books
Whole book
Format
Author AA, Author BB. Title of Book. Edition ed. Place of Publication: Publisher; Year.
Examples
5. Alberts B, Johnson A, Lewis J, Morgan D, Raff M, Roberts K, et al. Molecular Biology of the Cell. 7th ed. New York: Garland Science; 2022.
6. Sherwood L. Human Physiology: From Cells to Systems. 10th ed. Boston: Cengage Learning; 2021.
Chapter in an edited book
Format
Author AA. Title of chapter. In: Editor AA, Editor BB, editors. Title of Book. Edition ed. Place: Publisher; Year. p. StartPage-EndPage.
Example
7. Nguyen T. Apoptosis and cell signalling pathways. In: Brown P, Wilson C, editors. Cell Biology: Core Concepts. 3rd ed. London: Academic Press; 2021. p. 245-78.
Websites and Online Resources
Online sources should include the date you accessed the page, since web content can change. Use the organisation's name as author when no individual author is listed.
Format
Author/Organisation. Title of page [Internet]. Place: Publisher; Year [cited Year Month Day]. Available from: URL
Examples
8. World Health Organization. Global tuberculosis report 2023 [Internet]. Geneva: WHO; 2023 [cited 2024 Jan 10]. Available from: https://www.who.int/teams/global-tuberculosis-programme/tb-reports
9. National Institutes of Health. Understanding emerging and re-emerging infectious diseases [Internet]. Bethesda (MD): NIH; 2022 [cited 2024 Feb 5]. Available from: https://www.ncbi.nlm.nih.gov/
Conference Papers and Proceedings
Format
Author AA, Author BB. Title of paper. In: Editor(s) AA, editors. Title of Proceedings; Date of Conference; Location. Place: Publisher; Year. p. StartPage-EndPage.
Example
10. Park SY, Kim JH, Lee MJ. Biomarker discovery using mass spectrometry proteomics for early cancer detection. In: Chen L, editor. Proceedings of the 12th International Conference on Bioinformatics; 2023 Sep 15-18; Tokyo, Japan. New York: ACM; 2023. p. 201-8.
Theses and Dissertations
Format
Author AA. Title of thesis [dissertation/thesis]. [Place]: University Name; Year.
Examples
11. Almeida SM. The role of gut microbiome diversity in inflammatory bowel disease progression [PhD thesis]. London: University College London; 2022.
12. Park JY. Computational prediction of antibiotic resistance mutations in Mycobacterium tuberculosis [Master's thesis]. Seoul: Seoul National University; 2023.
Journal Abbreviations
Vancouver style uses abbreviated journal names from the NLM catalog. Below are common abbreviations used in life sciences:
| Full Journal Name | NLM Abbreviation |
|---|
| Nature Biotechnology | Nat Biotechnol |
| The New England Journal of Medicine | N Engl J Med |
| The Lancet | Lancet |
| Cell | Cell |
| Science | Science |
| PLOS Biology | PLoS Biol |
| The Journal of Biological Chemistry | J Biol Chem |
| Proceedings of the National Academy of Sciences | Proc Natl Acad Sci U S A |
| BMJ (British Medical Journal) | BMJ |
| Lancet Digital Health | Lancet Digit Health |
Finding abbreviations: search the NLM catalog at nlm.nih.gov/tsd/serials/lji.html. Type the full journal name and it returns the official abbreviation. Never guess an abbreviation — incorrect abbreviations are a common reason papers are rejected at submission.
Vancouver vs AMA — What Is the Difference?
Both Vancouver and AMA are numbered sequential citation systems used in biomedical fields. They look very similar but have some differences worth knowing:
| Feature | Vancouver | AMA |
|---|
| Author cutoff | 6 authors, then et al. | 3 authors (in some versions), then et al. |
| Year position | Year;Vol(Iss):pages | Year;Vol(Iss):pages (same) |
| Italics | No italics in references | No italics in references |
| Page separator | Hyphen: 512-525 | Hyphen: 512-525 |
| Used mainly in | Biology, medicine, nursing | Medical journals (JAMA standard) |
| In-text marker | Superscript or [brackets] | Superscript (preferred) |
If your institution specifies "Vancouver," use this guide. If it specifies "AMA," see our AMA citation guide. When neither is specified, check what journals in your field use — searching a paper in PubMed from a comparable journal will show you the house style.
Common Mistakes in Vancouver Style
- Alphabetical ordering: Vancouver reference lists are in citation order — numbered by when the source first appeared. Alphabetical ordering is the most common formatting error.
- Assigning a new number to a repeated source: if source 3 appears again later, it is still 3 — not a new number.
- Listing more than 6 authors without "et al.": list the first six, then "et al." — do not list all authors.
- Wrong author format: Vancouver uses Last Name Initials (no full stops) — Chen JK, not J.K. Chen or Jun K. Chen.
- Missing issue number: always include the issue in parentheses — 2023;41(4):512 — some students omit it.
- Using full journal names: journal titles must be abbreviated per NLM conventions, not written out in full.
- Italics in the reference list: Vancouver does not use italics for journal or book titles (unlike APA or Harvard).
- No access date for websites: always include "[cited Year Month Day]" for web sources.
Frequently Asked Questions
Should I use superscripts or square brackets?
Both are accepted variants of Vancouver. Superscripts (¹²³) are traditional; square brackets ([1][2][3]) are common in university assignments and easier to type. Check your institution's specific guidelines — if none are given, square brackets are generally safe and clear.
What if the same source is cited 10 times throughout my paper?
Use the same number every time. If source [4] is cited at the start, middle, and end of your paper, all three in-text citations read [4]. You only ever have one entry in the reference list for each unique source.
Do I need to include DOIs?
DOIs are increasingly expected and should be included when available. They are particularly important for journal articles because they provide a permanent, reliable link regardless of whether a journal changes its URL structure. Format as: doi:10.1016/xxxx (no space after the colon).
Can I use Vancouver for a systematic review or meta-analysis?
Yes — in fact, Vancouver is the standard for systematic reviews published in biomedical journals. When you search PubMed for systematic reviews, the vast majority will use Vancouver or NLM style. Follow the same rules as a regular journal article — the citation format for a primary study and a systematic review is identical.
What is the difference between Vancouver and NLM style?
NLM (National Library of Medicine) style is developed by the US National Library of Medicine and is closely aligned with Vancouver. The main difference is that NLM uses specific punctuation patterns in some reference types and is the official style for NCBI/PubMed publications. For most undergraduate and postgraduate assignments specifying "Vancouver," the formats are interchangeable.
My article has no volume or issue number — what do I do?
Some newer open-access journals publish articles continuously without traditional volume and issue numbers. In this case, include the article ID or DOI as the locator: Author AA. Title. Journal Abbrev. 2023;e112893. doi:10.xxxx/xxxxx