This meta-analytic review analyzed the effects of anger treatment on various aspects of anger with 65% of studies not previously reviewed. To improve on past reviews, this review included only noninstitutionalized adults with demonstrable anger as determined by standardized measures. The studies were compiled from a computer search of published and unpublished anger treatment studies conducted between January 1980 and August 2002. The search resulted in 23 studies containing one or more treatment groups and a control group, with effect sizes derived for each anger problem within each treatment category. The meta-analysis resulted in medium to large effect sizes across therapies. Further analyses of effect sizes within treatment groups by the kind of anger reported support the implementation of cognitive therapies for driving anger, anger suppression, and trait anger. In contrast, relaxation is recommended in cases of state anger. Other implications for treatment and future research directions are discussed, including a special need for research with treatment-seeking individuals and clinical populations.