Insomnia is one of the most common symptoms of posttraumatic stress disorder (PTSD). Evidence suggests that insomnia may persist for many PTSD patients after other symptoms have responded to cognitive-behavioral therapy (CBT). The present article reports the effects of administering a five-session cognitive-behavioral insomnia treatment to 5 patients who responded to CBT for PTSD yet continued to report insomnia. Insomnia treatment was associated with improvements on subjective sleep measures (Pittsburgh Sleep Quality Index, Insomnia Severity Index, and Beliefs and Attitudes about Sleep Scale) and self-monitored sleep efficiency and related measures in 4 of 5 cases. Results highlight issues specific to treating insomnia in trauma populations and future directions for examining treatment of insomnia associated with PTSD.