This study examined 184 African-American outpatients in a mental health clinic in the inner city to define the rate of occurrence of traumatic experience and posttraumatic stress disorder (PTSD). This population experienced a high rate of severe trauma. Forty-three percent were found to have PTSD, as measured by the PTSD Symptom Scale. Finally, a chart review of 72 participants found that only 11 percent of participants who met DSM-IV criteria for PTSD also had a chart diagnosis of PTSD. PTSD is a common yet underrecognized and undertreated source of psychiatric morbidity in this urban community of African Americans with low socioeconomic status.