Researchers and journal editors need to be familiar with the major and most widely-used indexing databases. The specific and sensitive searching ability of medical databases always help researchers to avoid redundant studies as well as to provide background to their work. The important medical databases from Korea are KoreaMed, KoreaMed Synapse, KoMCI and KMBase. Major international databases are WPRIM, Medline/PubMed, PubMed Central, Web of Science, SCOPUS, digital object identifier/CrossRef, Google Scholar, EMBASE, Biosis Previews, Worldwidescience.org, and the Cochrane Library. Although every database from Korea is freely accessible to anyone, some international databases require subscription fees. This is the reason why PubMed and PubMed Central, free access databases, have become the most important and widely used ones internationally. Easier access to databases not only from the Web but also from mobile environment applications will continue to develop. Physicians and researchers should be able to use both Web and mobile databases for better patient care and research. Editors should try to add their journals not only to databases from Korea but also to international databases in order to promote the health of all mankind by disseminating the medical information.