We studied 655 urban police officers (21% female, 48% white, 24% black, and 28% Hispanic) to assess ethnic and gender differences in duty-related symptoms of posttraumatic stress disorder (PTSD). We obtained self-report measures of: a) PTSD symptoms, b) peritraumatic dissociation, c) exposure to duty-related critical incidents, d) general psychiatric symptoms, e) response bias due to social desirability, and f) demographic variables. We found that self-identified Hispanic-American officers evidenced greater PTSD symptoms than both self-identified European-American and self-identified African-American officers. These effects were small in size but they persisted even after controlling for differences in other relevant variables. Contrary to expectation, we found no gender differences in PTSD symptoms. Our findings are of note because: a) they replicate a previous finding of greater PTSD among Hispanic-American military personnel and b) they fail to replicate the well-established finding of greater PTSD symptoms among civilian women.