Eight months after the Cerro Grande Fire, 78 evacuees seeking treatment for posttraumatic sleep disturbances were assessed for chronic nightmares, psychophysiological insomnia, and sleep-disordered breathing symptoms. Within this sample, 50% of participants were tested objectively for sleep-disordered breathing; 95% of those tested screened positive for sleep-disordered breathing. Multiple regression analyses demonstrated that these three sleep disorders accounted for 37% of the variance in posttraumatic stress symptoms, and each sleep disorder was significantly and independently associated with posttraumatic stress symptoms severity. The only systematic variable associated with posttraumatic stress symptoms of avoidance was sleep-disordered breathing. The findings suggest that three common sleep disorders relate to posttraumatic stress symptoms in a more complex manner than explained by the prevailing psychiatric paradigm, which conceptualizes sleep disturbances in PTSD merely as secondary symptoms of psychiatric distress.