This guide to collecting mental health court outcome data briefly discusses the process of identifying target the population and goals. It then provides practical strategies to operating courts for deciding which data to collect; obtaining, evaluating, and comparing the data; and overcoming common challenges. Outcome data can be of enormous value to courts in their efforts to demonstrate the initial promise of their approach and can help to attract researchers interested in conducting a more rigorous evaluation. Mental health courts usually receive initial funding based on their potential for positive impacts; they are funded in subsequent years based on their ability to demonstrate results. The ideas offered in this guide assume several things about mental health courts and the task of collecting data: mental health courts have allocated very little money to collecting outcome data; mental health court administrators and program staff are not experts in data collection; collecting outcome data is not a one-time research endeavor, but an ongoing effort to understand the mental health court’s impact over time, assessed periodically for budgeting, publicity, a meeting presentation, or to justify the court’s existence; and there are more resources available to a mental health court trying to collect outcome data than may be apparent initially. References, appendix