All 322 patients at a psychiatric clinic for Indochinese refugees were surveyed to determine the presence of posttraumatic stress disorder (PTSD). If PTSD was not diagnosed at the time of initial evaluation, a structured reinterview was performed. Seventy percent of the patients (N = 226) met the criteria for a current diagnosis of PTSD, and an additional 5% (N = 15) met the criteria for a past diagnosis. The Mein had the highest rate of PTSD (93%) and the Vietnamese the lowest (54%). Of the patients with PTSD who were enrolled in the clinic before March 1988, 46% (N = 87) were given a diagnosis of PTSD only after the reinterview. PTSD is a common disorder among Indochinese refugees, but the diagnosis is often difficult to make.