This study evaluates the relationship between stress of captivity and subsequent presence of Post Traumatic Stress Disorder (PTSD) has been evaluated in a homogeneous population of 817 Alsatian World War II veterans who were imprisoned in the USSR during and after the war. Data were collected in 1988 by a questionnaire structured to investigate the presence of DSM-III-R criteria for PTSD as well as events experienced in captivity. The presumptive diagnosis of PTSD was found to be significantly associated with longer internment and with higher scores on a severity of POW experience index.