The notion that sexual behavior can be compulsive, addictive, or otherwise out-of-control has received significant attention in the recent sexological, psychological, and public health literatures. Additionally, numerous clinicians and self-help groups have increased awareness of, and ˵treatments″ for, sexual addiction and sexually compulsive behavior. However, to date, there remains substantial debate and skepticism surrounding the nature and existence of sexual addiction (or sexual compulsivity) as a pathological condition. This chapter provides an overview of the historical foundations underlying contemporary perspectives on sexual compulsivity, a summary of the literature on the dominant theoretical perspectives on the clinical manifestations and etiology of sexual compulsivity. The primary measures being used by researchers to understand sexual compulsivity are summarized, including the Carnes΄ Addiction Model, Coleman΄s Compulsive Sexual Behavior Model, and Kalichman΄s Impulse Control Model, and a new scale focused on measuring both behavioral and cognitive outcomes of compulsive behavior is reviewed. The chapter concludes with recommendations for future research and clinical practice. [ABSTRACT FROM AUTHOR]