The objective of the present study was to examine psychological distress among adolescent and young adult prisoners within the first two weeks of imprisonment. In addition, their psychosocial background was explored. A total sample of N = 180 newly imprisoned males was investigated with regard to psychosocial distress, medical history, drug use, as well as socioeconomic and forensic background. Data were collected using the SCL-90-R and a standardized clinical documentation. The prevalence of cases with clinical relevant levels of psychological distress (clinical case) was high (69.4%). Many probands showed a remarkable history of drug use, delinquency, and other problem behavior prior to the imprisonment. Multiple regression and logistic regression analyses revealed that mental disorders of parents or siblings, foreign nationality, and somatic diseases were risk factors for psychological distress. The results underscore the need for improved clinical care in terms of psycho diagnostics, prevention, and intervention.