The use of surgical castration represents a gross misunderstanding of the nature and psychodynamics of sexual deviations. The paper reports on data on the sexual behavior of 39 released sex offenders who agreed voluntarily to surgical castration while imprisoned in West Germany. Findings indicate that frequency of coitus, masturbation, and sexual thoughts are seen as strongly reduced after castration. Sexual desire and sexual arousability are perceived by the subjects as having been considerably impaired by castration. However, in comparison with other studies, it is shown that male sexual capacity is not extinguished soon after castration. Eleven of 35 castrates stated that they were still able to engage in sexual intercourse. Rapists proved to be sexually more active after castration than homosexuals or pedophilliacs. Castration only seems to strongly affect sexual behavior if it is performed on males between the ages of 46 and 59 years. Tables and 15 references are supplied. (Author abstract modified)