Rape victims experience significant long-term problems in the areas of fear, anxiety, and depression, as well as difficulties in social adjustment and impaired sexual functioning. Further, being the victim of rape appears to be associated with an increased risk of suicide. There is general agreement that rape is the most underreported violent crime, and one reason for this may be the poor treatment of victims by the criminal justice system. Two major theoretical models have been proposed to explain rape. The first centers on the character pathology of the offender, while the second views social factors as causative. Rape has several unique characteristics: it is difficult to know how frequently rape occurs due to a low reporting rate; victims of rape are often held responsible for their own assaults and assailants are dismissed as not having committed a real offense; and rape is treated distinctively in the courtroom. Sources of data on the nature and extent of rape and sexual assault in the United States are noted. Causes and risk factors involved in sexual aggression are discussed, with reference to research on sexual offenders, victim characteristics, and victimization effects. The need to provide rape and sexual assault victims with a comprehensive system of services and resources is emphasized. 117 references