To make updated and unbiased answers to a clinical question, it is essential to effectively and efficiently search the medical literature. The goal of medical literature searching is comprehensive and transparent and is a replicable procedure to get correct conclusions to the question. To do this, each user should make well formulated clinical questions, and have knowledge on what specific characteristics each database has. There are several readily accessible English databases that provide literature information including PubMed, EMBASE, and CINAHL. The Korean medical literature database including Koreamed and KMBase are also available. Users can search information through formulated search terms such as in MeSH in Pubmed. Skills in finding and using search terms are essential in effective searching. Also knowledge on using filters is frequently needed to search database quickly for articles on several study designs. After running a search in the database, one needs to retrieve search results effectively. In comprehensive literature search, especially for writing a systematic review, one needs to include literature to overcome and minimize publication bias. This process often requires searching in gray literature, and the common types and sources of publication bias are described. Finally, we need to constantly validate search results, and revise the search through a continuous process. In this article, the basic concepts and procedures of searching medical literature are described.