THE GROUP WAS DRAWN FROM A LARGER SAMPLE OF 248 MALE OPIOID DRUG USERS WHO ARE SUBJECTS OF A CONTINUING LONGITUDINAL STUDY WHICH BEGAN IN 1966. BIOGRAPHICAL INFORMATION WAS COLLECTED FROM MANY SOURCES ALONG WITH URINE SPECIMENS. MOST HAD USED HEROIN, BEGINNING AT ABOUT AGE 17, AND HAD CONTINUED THE USE FOR AN AVERAGE OF 5 YEARS. MEDIAN EDUCATION WAS EIGHTH GRADE. IN ADDITION TO THE 7 SUBJECTS WHO REMAINED ABSTINENT FOR THE ENTIRE PROBATION YEAR, 17 ACHIEVED 6 MONTHS OR MORE OF ABSTINENCE. THIS COMPARES TO 12 WHO ACHIEVED 6 MONTHS OR MORE OF ABSTINENCE DURING THE PREPROBATION YEAR. AT THE END OF THE PROBATION PERIOD, 37 PERCET OF THE SUBJECTS WERE USING AN ILLICIT OPIOID DRUG ON A DAILY OR IRREGULAR BASIS AND 28 PERCET WERE BACK IN JAIL OR PRISON. A SMALL INCREASE IN EMPLOYMENT AMONG THE GROUP OCCURRED. THREE FACTORS PROBABLY ACCOUNT FOR THE LOW RATE OF ABSTINENCE: (1) MOST HAD NEVER BECOME SOCIALLY COMPETENT BEFORE PROBATION; (2) THEY DID NOT COME FOR ASSISTANCE VOLUNTARILY, BUT WERE FORCED INTO THE PROGRAM AFTER CONVICTION FOR LAW VIOLATION, AND (3) THE SUBJECTS RECEIVED ONLY ROUTINE PROBATION SUPERVISION. CASELOADS EXCEEDED 150, AND THE PROBATION OFFICER USUALLY SAW THE PROBATIONER ONLY ONCE A MONTH. THIS STUDY REPORTS A LOWER RATE OF ABSTINENCE THAN OTHER SIMILAR STUDIES. IT IS SUGGESTED THAT THIS IS BECAUSE THE INTERVIEWS WERE CONDUCTED AFTER THE PROBATION PERIOD HAD ELAPSED, WHEN ADMISSION OF DRUG USE WOULD NOT RESULT IN PAROLE REVOCATION. OTHER STUDIES HAVE CONDUCTED THE INTERVIEWS DURING THE PROBATION PERIOD WHEN MOTIVATION TO HIDE DRUG USE IS STRONG. STUDY DATA ARE PRESENTED IN A SERIES OF TABLES. REFERENCES ARE INCLUDED. (GLR)