The need for evaluation of drug abuse treatment programs has been generally recognized and mandated by law since 1976. To learn to what extent such evaluations are actually performed and to obtain information about those evaluations, drug abuse treatment programs receiving federal funds in 1979 were surveyed. Questionnaires were sent to a random sample of programs (N=628), with 341 responding (54%). Among the questions asked were the number of actual evaluations conducted, the way data were collected and analyzed, and the sources of the evaluation personnel. Responses were tabulated in terms of three categories of evaluation, i.e., in-treatment, follow-up, and process/cost. Results indicated that substantial numbers of programs receiving National Institute for Drug Abuse funding at the time of the survey had conducted recent evaluations of their programs. In-treatment evaluation was the most prevalent type of evaluation conducted, with follow-up evaluation conducted by 20% of the programs surveyed. Among the seven major conclusions were that: (1) larger treatment programs with greater resources were more likely to carry out evaluation; (2) program staff involvement in the evaluation process was widespread; and (3) significant changes in program operations resulted from the various program evaluations. (PAS)