A meta-analysis was conducted on 61 treatment outcome trials for post-traumatic stress disorder (PTSD). Conditions included drug therapies (TCAs, carbamazepine, MAOIs, SSRIs, and BDZs), psychological therapies (behaviour therapy, Eye-Movement Desensitization and Reprocessing (EMDR), relaxation training, hypnotherapy, and dynamic therapy), and control conditions (pill placebo, wait-list controls, supportive psychotherapies, and non-saccade EMDR control). Psychological therapies had significantly lower drop-out rates than pharmacotherapies (14% versus 32%), with attrition being uniformly low across all psychological therapies. In terms of symptom reduction, psychological therapies were more effective than drug therapies, and both were more effective than controls. Among the drug therapies, the SSRIs and carbamazepine had the greatest effect sizes, although the latter was based upon a single trial. Among the psychological therapies, behaviour therapy and EMDR were most effective, and generally equally so. The most effective psychological therapies and drug therapies were generally equally effective. Differences across treatment conditions were generally evident across symptom domains, with little matching of symptom domain to treatment type. However, SSRIs had some advantage over psychological therapies in treating depression. Follow-up results were not available for most treatments, but available data indicates that treatment effects for behaviour therapy and EMDR are maintained at 15-week follow-up. © 1998 John Wiley & Sons, Ltd.