This study describes the results of the first three years of operation of California's ongoing Narcotic Treatment-Control Project, estab lished by legislation in 1959.The program provides for: (1) assignment of parolees with a history of narcotics use to 30-man caseloads supervised by specially trained agents; (2) weekly narcotic detection testing of the parolees; and (3) mandatory short-term reconfinement and treatment for those detected reverting to narcotics us.Findings show that administration of nalline testing was accom panied by a significant decrease in those using narcotics, and in jail and prison returns. There was some indication that the full program, including treatment, is making the program of control further effective. Treatment aspects are currently under further evaluation.