PubMed is a project developed by the National Centre for Biotechnology Information (NCBI) at the National Library of Medicine (NLM), located at the National Institutes of Health (NIH). It has been developed in conjunction with publishers of biomedical literature as a search tool for accessing literature citations and linking to full-text journals at Web sites of participating publishers.

Publishers participating in the PubMed project supply NLM with formatted citations before or at the time of publication, and NLM adds them to the PubMed search system. If the publisher has a website that offers the full text of its journals, PubMed provides links to that site.

The PubMed search system provides access to the PubMed database of bibliographic information, which is drawn primarily from MEDLINE and PREMEDLINE. Also, for participating journals that are indexed selectively for MEDLINE, PubMed includes all articles from that journal, not just those that are included in MEDLINE. Finally, PubMed also provides access to the molecular biology databases included in NCBI's Entrez retrieval system.