As drug courts are implemented across the country, there is a corresponding need for descriptions and evaluations of program outcomes, particularly those related to substance abuse and criminal behavior among program participants. Evidence is needed to inform public policy with regard to the optimal length of drug court programs, the most effective blend of program services, and characteristics of defendants who are most likely to benefit from those strategies. This document presents information on: (1) how evaluation information should be used; (2) evaluation design and implementation strategies, including how to obtain participant cooperation and involving participating agencies in the evaluation process; (3) developing an evaluation data system; (4) types of evaluation approaches; (5) other program evaluation issues; and (6) protection of confidentiality and data security. Appendixes