Prostate cancer is the most common non-skin cancer diagnosed in men in the United States. Almost all newly diagnosed patients receive some form of treatment, despite a majority of diagnoses representing non-aggressive cases. Treatment is associated with lowered health-related quality of life (QOL). Lowered QOL in cancer survivors is experienced as any/all of an array of physical symptoms, including sexual, urinary, and bowel dysfunction, and of psychological symptoms, including increased likelihood of depression, anxiety, and social dysfunction. Few studies in prostate cancer have examined the relationship between treatment side effects and traumatic stress responses. The aims of this study were to 1) describe, in men with prostate cancer, the levels of traumatic stress responses of intrusion, avoidance, and hyperarousal, and 2) predict levels of traumatic stress responses from patient-reported prostate cancer treatment side effects of urinary, bowel, and sexual dysfunction, controlling for sociodemographic and clinical factors. Participants were 164 prostate cancer survivors, all of whom had a spouse or live-in partner. Participants completed the Impact of Event Scale-Revised (IES-R) and the UCLA Prostate Cancer Index (PCI), and provided sociodemographic data. Descriptive analyses were conducted to assess the levels of traumatic stress responses on the IES-R, and levels of prostate cancer side effects self-reported on the PCI. Hierarchical linear regression analyses were conducted, controlling for covariates, in which the Total and three subscale scores from the IES-R were regressed on scores of Urinary, Bowel, and Sexual dysfunction. Logistic regression analysis was conducted, controlling for covariates, in which clinical group membership, based on IES-R cut-offs, was regressed on Urinary, Bowel, and Sexual dysfunction scores. In terms of traumatic stress response, 29.88% met the threshold on the IES-R for a probable diagnosis of post-traumatic stress disorder. Mean subscale scores for Avoidance, Intrusion, and Hyperarousal were similar to other samples of prostate cancer survivors. Urinary dysfunction significantly predicted the IES-R Hyperarousal score; Bowel and Sexual dysfunction were not significant predictors. Urinary, Bowel, and Sexual dysfunction were not significant predictors of clinical group membership in a logistic regression analysis. Interventions for urinary dysfunction should be further validated and taught to prostate cancer patients.