We describe and illustrate our system to measure, monitor, and feed back information about patient treatment. This clinical innovation relies on research-based clinical decision tools that provide psychotherapists with timely warnings when a patient's deviation from an expected treatment response foretells possible treatment failure. We summarize the results of four controlled studies using this methodology; the collective results suggest that measuring, monitoring, and predicting treatment failure (feedback) enhance treatment outcomes for patients who have a negative response. Clinicians are encouraged to employ these methods in routine practice despite their confidence in their own ability to predict patient outcome. © 2004 Wiley Periodicals, Inc. J Clin Psychol/In Session.