Given the increasing interest in demonstrating effectiveness in psychiatric treatment, the current paper seeks to advance outcome measurement in child psychiatry by demonstrating how more informative analytic strategies can be used to evaluate treatment in a real world setting using a brief, standardized parent-report measure. Questionnaires were obtained at intake for 1294 patients. Of these, 695 patients entered treatment and 531 (74%) had complete forms at intake and follow-up. Using this sample, we analyzed the data to determine effect sizes, rates of reliable improvement and deterioration, and rates of clinically significant improvement. Findings highlighted the utility of these approaches for evaluating treatment outcomes. Further suggestions for improving outcome measurement and evaluation are provided.