Social readaptation of persons released from prisons is a crucial means of preventing recidivism, as their social contacts and skills have been reduced by their prison stay. Furthermore, ex-convicts are frequently alienated from their immediate social sphere. The amount of resocialization needed varies widely from individual to individual. Steps of readaptation after release from prison include apprenticeship in new social roles, rebuilding of social relationships, expansion of the area of social contacts, and cooperation with broader circles of society. The success of resocialization depends to a large extent on the support and values of the releasee's family, and the educative influence of the working collective. Releasees may have initial difficulties adapting to work because of alienation, feeling that demands on them are excessive, that there are poor internal relations at the work collective and a lack of personal relationships with fellow workers. Ex-convicts adapt best to the work collective when they are well paid and the collective has a positive attitude. Adaptation to the work collective begins with professional activities, progresses to acceptance of the moral models and values of the collective, and finally extends to work collective contacts in free time and daily life. Intervention may be required to avoid conflicts in the process. Individuals who remain alienated from the work collective are likely to become involved once again in criminal activities. Ex-convicts with adaptation problems after release can be categorized as persons who have lost social skills and contacts to an immediate social circle, persons with disturbances in social interaction, and persons with weak social interaction. The first group is most likely to become recidivists. Moreover, poor adaptation to the work collective is most frequent among individuals with little work experience and inadequate professional qualifications. Ex-convicts with readaptation problems are likely to seek out the company of street people whose value systems approximate theirs and where the environment favors criminal activity. Social control of ex-convicts may be informal, based on moral principles and norms, or official, based on law. As the informal method of control has been disrupted by the living circumstances in urban areas, some criminologists believe that the official mode of control must be developed. But it should be recognized that official control alone is not adequate to assure effective prevention of recidivism.