IT IS NOTED THAT SIGNIFICANT DIFFERENCES BETWEEN MENTALLY RETARDED OFFENDERS AND GENERAL OFFENDERS EXIST, AND THAT REHABILITATION EFFORTS FOR THE MENTALLY RETARDED WILL FAIL IF THESE DIFFERENCES ARE NOT RECOGNIZED. THE PIMA COUNTY PILOT PROJECT WAS FOUNDED IN ORDER TO DEAL WITH THE SPECIAL PROBLEMS OF THE MENTALLY RETARDED PROBATIONER. THE PROJECT EXPERIMENTED WITH SEVERAL METHODS OF SCREENING PROBATIONERS FOR MENTAL RETARDATION BEFORE FINDING A TECHNIQUE WHICH WAS BOTH EFFECTIVE AND PRACTICAL. UNDER THIS METHOD, ALL PROBATIONERS ARE ADMINISTERED A SIMPLE TEST WHICH CAN INDICATE THE POSSIBILITY OF MENTAL RETARDATION. PERSONS WHOSE TESTS INDICATE THIS POSSIBILITY ARE THEN REFERRED TO THE COURT CLINIC FOR FURTHER TESTS. A SPECIALIZED REHABILITATION PROGRAM WAS ALSO DEVELOPED FOR THESE PROBATIONERS. THE PROGRAM DISCOVERED THAT MENTALLY RETARDED PROBATIONERS OFTEN CANNOT UNDERSTAND PROBATION CONDITIONS, WHICH CAN CAUSE THEM TO VIOLATE THOSE CONDITIONS. THIS PROGRAM UTILIZES INTENSIVE COUNSELING, ENVIRONMENTAL MANIPULATION, AND ESTABLISHMENT OF SUPPORTIVE RELATIONSHIPS TO AID THE PROBATIONERS. PRELIMINARY RESULTS OF THE PROJECT ARE BRIEFLY REVIEWED AND ASSETS AND LIABILITIES OF THE PROJECT ARE DISCUSSED.