Drug abuse programs in New York City schools were evaluated to determine their natures, whether they met the needs of students, and the outcomes realized. Programs have been in operation for 15 years. Students selected from 32 programs were given pretests with posttests after participation. Three instruments were used. Valid matched testings were obtained for 1,799 elementary and secondary students. Twenty-seven variables were identified as quantifying program effectiveness. Of these, 14 were cognitive, representing significant changes in attitudes or more complex thinking processes related to substance abuse. The school district drug abuse prevention programs were found to have a significant impact on some participants. Attitudes, complex cognitions about authority and family, and behaviors were affected in ways that reduced the frequency or likelihood of drug use. Significant beneficial change was noted for 30% of the students. Needed improvement is suggested by the fact that 70% were unaffected by participation. The evaluation also resulted in establishment of a data bank of baseline information and the instrumentation for assessing program effectiveness. Nine graphs provide city-wide and district-wide data. District findings are summarized in 63 tables. (SLD)