Subjects were a random sample of all German men released from Lower Saxony prisons in 1974 (N=367) and 153 ex-inmates released in the same year who had participated in vocational or academic training courses during their correctional terms. Data were collected from the institutional files (personal characteristics) and from the central criminal records office (criminal career and reconvictions within 5 years after release). The recidivism rate of ex-offenders released from Lower Saxony prisons in 1974 was 68 percent within 60 months after release; 39 percent of all new offenses occurred within 6 months after release. Property offenders, traffic violators, and drug addicts tended to commit again the same offenses, respectively. The recidivism rate of adult prisoners participating in training courses did not differ from that of adult nonparticipants, but with successful participants of training courses, the recidivism rate was only 62 percent and appreciably lower than that of nonparticipants (72 percent). Still, no variables have so far been found that would enable the individual prediction of successful participation in training courses. The same research is to be continued further to assess the possible relationship between institutional management, situation upon release, and recidivism. Charts, footnotes, tabular data, and 38 references are given. (Author abstract modified)