Data were collected on three groups of sex offenders: offenders against adults, offenders against non-relative minors, and offenders against minors with incest. Results showed that offenders against adults were younger, were more frequently single, and had a lower educational level than offenders against minors. Incest offenders had no prior convictions, compared to 50 percent of other offenders. Violence was more often used by offenders against adults than by offenders against minors. About two-thirds of offenders had no psychiatric history, but a personality disorder (mainly borderline) was diagnosed in half the offenders. A history of sexual abuse during childhood was reported by one-third of offenders against minors and by 5 percent of offenders against adults. Low socioeconomic status and social isolation characterized offenders against adults, whereas offenders against minors had a relatively normal psychosocial profile. The challenge for forensic psychiatrists to prevent the drift of paraphilia toward crime is discussed. 20 references and 4 tables