Systematic literature searches in bibliographic databases are an essential step in constructing systematic reviews and health technology assessments. The purpose of this kind of search is to identify as many relevant references on a given topic in electronic databases as possible. This article begins with describing the search process and continues with the basics of searching electronic databases. By delivering insight into the functionalities of databases and possibilities to search them (particularly PubMed), an understanding of potentials and weaknesses of systematic literature searches should be established.