We examined the therapeutic efficacy of a culturally adapted cognitive-behavior therapy for Cambodian refugees with treatment-resistant posttraumatic stress disorder (PTSD) and comordid panic attacks. We used a cross-over design, with 20 patients in the initial treatment (IT) condition and 20 in delayed treatment (DT). Repeated measures MANOVA, Group & times; Time ANOVAs, and planned contrasts indicated significantly greater improvement in the IT condition, with large effect sizes (Cohen's d) for all outcome measures: Anxiety Sensitivity Index (d = 3.78), Clinician-Administered PTSD Scale (d = 2.17), and Symptom Checklist 90-R subscales (d = 2.77). Likewise, the severity of (culturally related) neck-focused and orthostasis-cued panic attacks, including flashbacks associated with these subtypes, improved across treatment.