Accurate estimates of prevalence/incidence are important in understanding the true burden of male and female sexual dysfunction and in identifying risk factors for prevention efforts. This is the summary of the report by the International Consultation Committee for Sexual Medicine on Definitions/Epidemiology/Risk Factors for Sexual Dysfunction. The main aim of this article is to provide a general overview of the definitions of sexual dysfunction for men and women, the incidence and prevalence rates, and a description of the risk factors identified in large population-based studies. Literature regarding definitions, descriptive and analytical epidemiology of sexual dysfunction in men and women were selected using evidence-based criteria. For descriptive epidemiological studies, a Prins score of 10 or higher was utilized to identify population-based studies with adequately stringent criteria. This report represents the opinions of eight experts from five countries developed in a consensus process and encompassing a detailed literature review over a 2-year period. The study aims to provide state-of-the-art prevalence and incidence rates reported for each dysfunction and stratified by age and gender. Expert opinion was based on the grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate. A wealth of information is presented on erectile dysfunction, its development through time, and its correlates. The field is still in need of more epidemiological studies on the other men's sexual dysfunction and on all women's sexual dysfunctions. A review of the currently available evidence from epidemiological studies is provided.