Hypersexual Disorder is proposed as a new psychiatric disorder for consideration in the Sexual Disorders section for DSM-V. Historical precedents describing hypersexual behaviors as well as the antecedent representations and proposals for inclusion of such a condition in the previous DSM manuals are reviewed. Epidemiological as well as clinical evidence is presented suggesting that non-paraphilic "excesses" of sexual behavior (i.e., hypersexual behaviors and disorders) can be accompanied by both clinically significant personal distress and social and medical morbidity. The research literature describing comorbid Axis I and Axis II psychiatric disorders and a purported relationship between Axis I disorders and Hypersexual Disorder is discussed. Based on an extensive review of the literature, Hypersexual Disorder is conceptualized as primarily a nonparaphilic sexual desire disorder with an impulsivity component. Specific polythetic diagnostic criteria, as well as behavioral specifiers, are proposed, intended to integrate empirically based contributions from various putative pathophysiological perspectives, including dysregulation of sexual arousal and desire, sexual impulsivity, sexual addiction, and sexual compulsivity.