Among Cambodian refugees attending a psychiatric clinic (n=100), 49% (49/100) had at least one episode of sleep paralysis (SP) in the previous 12 months. The annual and monthly SP prevalences were much higher in posttraumatic stress disorder (PTSD) than in non-PTSD patients. Among the PTSD patients, 65% (30/46) had monthly episodes of SP versus 14.85% (8/54) among non-PTSD patients (χ2[2, n=100]=26.78, P<.001). Moreover, patients with SP in the last month (n=30) versus those without SP had much higher PTSD severity scores. In the entire sample (n=100), the PTSD severity scores correlated significantly with the rate of SP in the last month. During SP, Cambodian refugees usually hallucinated an approaching figure (90%, 44/49). The rate of SP-associated and post-SP panic attacks was high, indicating the great distress caused by the phenomenon. SP seems to be a core aspect of the Cambodian refugee's response to trauma. When treating Cambodian refugees, and traumatized refugees in general, clinicians should assess for its presence. Depression and Anxiety 22:47–51, 2005. © 2005 Wiley-Liss, Inc.