This paper reports on an open trial of metacognitive therapy (MCT) for chronic PTSD. MCT does not require imaginal reliving, prolonged exposure, or challenging of thoughts about trauma. It is based on an information-processing model of factors that impede normal and in-built recovery processes. It is targeted at modifying maladaptive styles of worry/rumination and attention so that emotional processing can proceed spontaneously. Eleven out of 13 patients with a mean duration of PTSD of 19.5 months completed treatment. Therapists followed the treatment manual by Wells and Sembi (2004b). Self-report measures of PTSD symptoms, anxiety and depression, and assessor ratings of PTSD were administered at pre- and posttreatment, and at 3- and 6-month follow-up. Treatment appeared to result in large and significant improvements on all measures of PTSD and general measures of anxiety and depression. Statistically significant treatment gains were maintained at 3- and 6-month follow-up. Jacobson's criteria for recovery showed that 90% of patients were recovered at posttreatment. At 6-month follow-up approximately 89% were recovered or reliably improved. Results suggest that MCT could be highly effective and extend evidence of its applicability to more treatment-resistant chronic PTSD cases. Comparisons against other active interventions are now clearly indicated. (Contains 1 table.)