Objective: We review all available controlled outcome studies of solution-focused brief therapy (SFBT) to evaluate evidence of its effectiveness. Method: Forty-three studies were located and key data abstracted on problem, setting, SFBT intervention, design characteristics, and outcomes. Results: 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. Conclusion: 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. (Contains 6 tables and 1 figure.) [A list of SFBT Outcome Studies is included.]