OBJECTIVES: Post-traumatic stress disorder (PTSD) is a difficult-to-treat sequel of combat. Data on effectiveness of alternate treatment structures are important for planning veterans' psychiatric services. The present study compared clinical presentations and treatment outcomes for Australian veterans with PTSD who participated in a range of models of group-based treatment. METHOD: Participants consisted of 4339 veterans with combat-related PTSD who participated in one of five types of group-based cognitive behavioural programmes of different intensities and settings. Data were gathered at baseline (intake), as well as at 3 and 9 month follow up, on measures of PTSD, anxiety, depression and alcohol misuse. Analyses of variance and effect size analyses were used to investigate differences at intake and over time by programme type. RESULTS: Small baseline differences by programme intensity were identified. Although significant improvements in symptoms were evident over time for each programme type, no significant differences in outcome were evident between programmes. When PTSD severity was considered, veterans with severe PTSD performed less well in the low-intensity programmes than in the moderate- or high-intensity programmes. Veterans with mild PTSD improved less in high-intensity programmes than in moderate- or low-intensity programmes. CONCLUSION: Comparable outcomes are evident across programme types. Outcomes may be maximized when veterans participate in programme intensity types that match their level of PTSD severity. When such matching is not feasible, moderate-intensity programmes appear to offer the most consistent outcomes. For regionally based veterans, delivering treatment in their local environment does not detract from, and may even enhance, outcomes. These findings have implications for the planning and purchasing of mental health services for sufferers of PTSD, particularly for veterans of more recent combat or peacekeeping deployments.