No review of the topic of swinging has been done in the last 20 years. This review is intended to update the literature. Studies estimating the incidence of swinging, the demographic and personality characteristics of swingers, along with how swingers are perceived by nonswingers are reviewed. Numerous theories explaining this behavior have been presented with a social psychological model being the primary focus here. Major reasons for getting involved in swinging, initiation into the lifestyle, effects on marriage, and dropping out of swinging are also covered. Finally, the literature dealing with some of the major problems with swinging, focusing on AIDS, are also discussed, along with the current state of swinging and suggestions for future research.