Interviews were conducted with the offenders, their probation officers, offenders' relatives, victims or their family members, and therapists. The tests used were the Sex Offender Study Questionnaire, the Wide Range Achievement Test (revised), The State-Trait Anger Inventory, and the Child Abuse Potential Scale. The types of sex offenders included child molesters, exhibitionists, obscene phone callers, rapists, and sexual assaulters. The percentage of offenders molested as children was no greater than that of the general population, and the offenders were employed in somewhat lower occupational statuses than might have been expected from their education. The offenders in general had lower trait and state anxiety scores than did patients in Veterans Administration hospitals, jail inmates, and undergraduate students. They had lower trait and state anger scores than undergraduate students and military recruits. A high percentage lacked social skills, a finding similar to other studies. Probation officers were limited in clinical knowledge of sexual offenders. The therapists who responded did not report favorable prognoses for most offenders. Among the study recommendations are that a unit of specially trained probation officers be used with sex offenders and that special behavior modification programs be developed for the offenders. 12 tables, 142 references, and appended forms.