To explore the relationship between posttraumatic stress disorder (PTSD) and quality of life (QOL)/psychological outcome in young adult survivors of childhood cancer. Cross-sectional, descriptive study. A large comprehensive pediatric cancer center on the West Coast. Fifty-one young adult survivors of childhood cancer, 18-37 years of age, disease free, and off treatment for an average of 11 years (range 2.8-26.7 years). A structured clinical interview was used to establish a PTSD diagnosis. Self-report instruments were used to assess QOL (RAND SF-36) and psychological distress (Brief Symptom Inventory (BSI)). Survivors with and without PTSD were compared on the BSI and RAND SF-36. PTSD status, QOL and psychological distress. Eleven subjects (20%) met full criteria for PTSD. Significant group differences were found for 17 of the 18 outcome variables. Survivors with PTSD reported clinically significant levels of psychological distress, whereas symptom levels for those without PTSD fell well within population norms. On all domains, QOL scores were significantly lower for the PTSD group compared to the non-PTSD group. PTSD in survivors of childhood cancer is related to long-term outcome. PTSD is associated with a poorer QOL (physical and mental) and an increase in psychological distress. Data suggest that survivors with PTSD have significant functional limitations and psychological comorbidity. Screening cancer survivors for PTSD will identify high-risk patients who need further evaluation and intervention.