Recent reviews of evidence-based treatment for depression did not identify behavioral activation as an evidence-based practice. Therefore, this article conducted a systematic review of behavioral activation treatment of depression, which identified three meta-analyses, one recent randomized controlled trial and one recent follow-up of an earlier randomized control trial. Behavioral activation was consistently superior to wait list and treatment as usual control groups. Effect sizes were not different from cognitive behavior therapy or cognitive therapy, both post-treatment and at follow-up. Indeed, behavioral activation may be more effective than cognitive therapy and cognitive behavior therapy in terms of lower dropout. Behavioral activation, like cognitive behavior therapy, may be superior to paroxitine because it results in less relapse and recurrence, may be substantially cheaper, and does not have risks of pharmacotherapy. There is some evidence that behavioral activation may also be useful with some people for whom cognitive and cognitive-behavior therapy is less effective, such as those with severe, lifelong depression, people with substance abuse and people with dementia and severe depression. There is now sufficient evidence to conclude that behavioral activation is an evidence-based therapy.