The spread of the international AIDS pandemic has drawn attention to the urgent need for data on human sexual behavior; yet the lack of an established tradition of theory and method in sex research has limited the development of research initiatives in this area. This has been particularly true in the study of homosexual and bisexual behavior, which has relied heavily on the use of quantitative survey methods that largely fail to address cross‐cultural differences in the structure and meaning of same‐sex sexual experience. More qualitative approaches offer the possibility of investigating homosexual and bisexual behavior within a broader social and cultural context and can therefore play an important role in developing a framework for the comparative analysis of behavioral data. This article seeks to contribute to the development of theory and method in sex research by outlining key research issues and possible methodologies for the qualitative investigation of homosexual and bisexual behavior in relation to HIV/AIDS.