In an attempt to develop a brief treatment for disaster survivors, the present study examined the effectiveness of a single session of modified behavioral treatment in earthquake-related posttraumatic stress disorder. Fifty-nine earthquake survivors in Turkey were randomized into either single-session modified behavioral treatment (SSBT) designed to enhance sense of control over earthquake-related fears or waiting list control condition (WL). The WL group received SSBT after a second baseline assessment. Follow-ups were at weeks 6, 12, 24, and at 1–2 years posttreatment. Significant treatment effects were found on all measures at posttreatment. The improvement rate was 49% at week 6; it rose to 80% by week 12, 85% by week 24, and 83% by the 1–2-year follow-up. Brief behavioral treatment has promise as a cost-effective intervention for disaster survivors.