Co-occurring cocaine use and posttraumatic stress disorders are prevalent and associated with negative treatment, health and societal consequences. This study examined the relationships among PTSD symptoms, gender, and cocaine use problems. Within a cross-sectional design, we gathered archival point prevalence data on new admissions (n = 573) to three addiction treatment agencies. Demographic, substance use, and PTSD symptom information were collected across the three agencies. Logistic regression analyses revealed that patients with cocaine use disorders had a two-fold increased odds for a probable PTSD diagnosis, compared to patients without a cocaine use disorder (OR = 2.19, 95% CI = 1.49-3.22, p < 0.001). Among females with cocaine use disorder, multinomial regression yielded a significant increase in the risk of moderate (RRR = 2.12, 95% CI = 1.10-4.10, p < 0.05) and severe (RRR = 2.87, 95% CI = 1.33-6.21, p < 0.01) PTSD symptoms. Males with cocaine use disorders had a two-fold increase in the risk of moderate PTSD symptoms (RRR = 2.13, 95% CI = 1.23-3.68, p < 0.01), but had no increased risk of developing severe PTSD symptoms (RRR = 1.93, 95% CI = 0.85-4.39, p = 0.117). Cocaine use appears to impact the risk of PTSD symptoms, especially in females. Future research should explore the generalizability of these findings to more racially and ethnically diverse samples, as well as among persons with this comorbidity who are not engaged in treatment services.