This report shows a series of prognosis-data drawn from an examination of the social situation of all "lifers", who were released from prison in Lower Saxony between 1945 and 1973. The main point of the analysis is the high rate of over 90% of successful post-institutional legal behaviour. For most of the ex-convicts an increase in income and a higher job satisfaction (upward social mobility) were registered after release from prison; family integration is another explanation for the high rate of successful behaviour. On the other hand a long term of imprisonment destroys prisoners' ability to fit into society. The potentiality to social activity diminishes, family ties break down and the burden of the results of imprisonment -- a dangerous influence on the process of reintegration -- increases. Age and prison adjustment behaviour are mostly irrelevant as prognosis-criteria.