We review all available controlled outcome studies of solution-focused brief therapy (SFBT) to evaluate evidence of its effectiveness. Forty-three studies were located and key data abstracted on problem, setting, SFBT intervention, design characteristics, and outcomes. Thirty-two (74%) of the studies reported significant positive benefit from SFBT; 10 (23%) reported positive trends. The strongest evidence of effectiveness came in the treatment of depression in adults where four separate studies found SFBT to be comparable to well-established alternative treatments. Three studies examined length of treatment and all found SFBT used fewer sessions than alternative therapies. The studies reviewed provide strong evidence that SFBT is an effective treatment for a wide variety of behavioral and psychological outcomes and, in addition, it may be briefer and therefore less costly than alternative approaches.