THE METHADONE MAINTENANCE PROGRAM, OPERATED BY THE LONG ISLAND JEWISH-HILLSIDE MEDICAL CENTER HAS A CAPACITY OF 226 PATIENTS. THE PROGRAM HAS A HIGH STAFF TO PATIENT RATIO (1 TO 17) AND PROVIDES A NUMBER OF ANCILLARY SERVICES, INCLUDING COMPREHENSIVE MEDICAL CARE, SOCIAL WORK SERVICES, AND COUNSELING AND PSYCHIATRIC EVALUATION. SINCE PROGRAM INCEPTION, THE RETENTION RATE HAS BEEN 80 PERCENT AND THERE HAS BEEN LITTLE STAFF TURNOVER. ARREST INFORMATION ON PATIENTS IN THE PROGRAM WAS PROVIDED BY STATE CRIMINAL JUSTICE AGENCIES. OF 226 PATIENTS, 80 GAVE THEIR PERMISSION TO RELEASE RAP SHEETS. DATA FROM THE RAP SHEETS WERE ANALYZED TO PORTRAY ARREST PATTERNS FROM 18 YEARS OF AGE TO THE TIME OF STUDY. ARREST RATES FOR DRUG AND NONDRUG OFFENSES WERE COMPUTED FROM 18 YEARS OF AGE TO THE TIME OF ENTRY INTO TREATMENT. THESE ARREST RATES WERE COMPARED WITH DATA DERIVED FROM THE TIME OF ENTRY INTO TREATMENT TO THE TIME OF STUDY (30 MONTHS). DEMOGRAPHIC DATA FOR THE SAMPLE AND FOR THE ENTIRE PATIENT POPULATION IN THE PROGRAM WERE COLLECTED FROM CASE RECORDS. FOR THE 80 PATIENTS, BOTH THE RATE OF ARREST AND THE NUMBER OF PATIENTS ARRESTED DECLINED IN RELATION TO ENTERING THE METHADONE MAINTENANCE PROGRAM. THE DECLINE WAS STATISTICALLY SIGNIFICANT FOR DRUG-RELATED OFFENSES BUT NOT FOR NONDRUG-RELATED OFFENSES. THE OVERALL DECLINE IN ARRESTS WAS DUE TO THE DECREASE IN DRUG-RELATED ARRESTS WHICH PLAYED A DOMINANT ROLE IN THE CRIMINALITY OF SUBURBAN PATIENTS. THE STUDY FINDINGS TEND TO CONFIRM PERSONS WHO CLAIM THAT METHADONE MAINTENANCE HAS NOT LIVED UP TO ITS POTENTIAL IN TERMS OF SHARPLY REDUCING INNER-CITY ADDICT CRIME BUT, AT THE SAME TIME, INDICATE METHADONE MAINTENANCE IS SURPRISINGLY MORE EFFECTIVE WITH SUBURBAN PATTERNS OF ADDICTION THAN THOUGHT TO BE THE CASE PREVIOUSLY. SUPPORTING DATA AND REFERENCES ARE PROVIDED. (DEP)