The textbook examines the physiological foundations of sexuality, features of human psychosexual development, issues of norm and pathology in sexology, as well as the prevention of sexually transmitted diseases. The section of criminal sexology covers the problems of abnormal sexual behavior and sexual crimes. The biological, sociocultural, and psychological mechanisms of the development of abnormal sexuality, the causes and motives that encourage the commission of criminal acts are analyzed, and ways to prevent sexual crimes are identified. For students of all specialties, psychologists, psychiatrists, sexologists, lawyers, criminologists and law enforcement officers.