Lifetime prevalence of traumatic events and current PTSD was assessed among 142 mental health consumers with serious mental illness served by a psychosocial rehabilitation day program. Lifetime exposure to trauma was high (87%). The rate of PTSD based on the PTSD Checklist (PCL) was also high (19-30% depending on different scoring criteria). Overall, the PCL had strong internal reliability for this sample. Documentation of trauma and PTSD was exceptionally low in medical records. Results suggest that trauma and PTSD are significantly overlooked in the public mental health system. Improved recognition of trauma and PTSD are needed in order to provide meaningful services to this highly vulnerable population.