The focus group is a technique for eliciting information from specific population subgroups. Issues addressed may be little known or relatively well known to the researcher. The method is most effectively used when the objective of the investigation is to elicit points of view of client or consumer groups which may differ from those of providers. Despite the frequency with which focus groups are used, few published materials describe the practical application of the method. This paper presents a detailed methodology for the conduct of focus groups and analysis of focus-group data with the intention of improving its use among researchers and health-care professionals. Data from two studies, immunization compliance in West Africa, and barriers to use of prenatal-care services in Bolivia, are used as illustrative examples.