The present study examined the impact of comorbid posttraumatic stress disorder (PTSD) on health-related quality of life and objective measures of health service utilization in 165 male veterans who have primary schizophrenia. Comorbid PTSD was assessed with the PTSD Checklist. Comorbid PTSD was significantly associated with decreased quality of life and increased medical service utilization, including increased psychiatric hospitalization and increased outpatient physical health visits, even after controlling for other clinical and demographic variables among this sample of patients who had primary schizophrenia. Veterans who have schizophrenia should be screened carefully for exposure to trauma and posttraumatic stress disorder.