Life-threatening illness has been identified as a stressor that can precipitate posttraumatic stress disorder (PTSD). Major advances in cancer treatment have led to increased survival periods. At the same time, there is a growing awareness of the psychological impact of cancer diagnosis and treatment on the patient. Cancer survivors report that cancer can elicit symptoms of traumatic stress. When cancer-related PTSD is untreated, medical and psychiatric morbidity increase. Despite the prevalence, impact, and morbidity of cancer-related PTSD, access to mental health care in cancer patients remains limited. It is important to increase mental health providers' awareness of cancer-related PTSD, given rising cancer rates and the potential for enhancing quality of life. This article presents an overview of the recognition, diagnosis, management, and follow-up of cancer-related PTSD for the mental health clinician.