Experimental diversion programs began in the late 1960's and generally excluded drug abusers. The success of these programs encouraged expansion into drug treatment diversion programs, and in 1972, the Treatment Alternatives to Street Crime (TASC) program was established to enable local jurisdictions to establish systems of identification and drug treatment referral for individuals in contact with the criminal justice system. By the end of 1975, TASC had funded 36 projects. Other nonfederal projects include the Court Referral Project in New York City, the Narcotics Diversion Project in Washington, D.C., and diversion programs in Massachusetts and California. Although diversion is claimed to be lower in cost than similar services, no research exists which compares the effectiveness of drug diversion with treatment provided at other points in the criminal justice process. In assessing the validity of diversion, it is important to compare the performance of drug diversion programs and the regular criminal justice system in dealing with drug abuse and future drug-related and nondrug-related criminal behavior. Methodological difficulties in designing valid comparisons do exist, but such comparisons are necessary for policy decisions on expansion or suspension of drug diversion programs. Current research is impressionistic rather than factual and focuses on the programs themselves rather than on their impact on client behavior. Much research and evaluation have been limited to measuring recidivism during treatment with little, if any, research which tracks graduates and dropouts and compares their recidivism rates to those of people processed normally through the criminal justice system. A total of 13 references are included.