A FOLLOWUP STUDY WAS CONDUCTED COMPARING A REPRESENTATIVE GROUP OF MEN REFERRED FROM DETOXIFICATION CENTERS TO HALFWAY HOUSES WITH A MATCHED CONTROL GROUP OF MEN WHO DID NOT ENTER HALFWAY HOUSES. ALL FIRST ADMISSIONS TO 3 DETOXIFICATION CENTERS IN A LARGE METROPOLITAN AREA WERE MONITORED OVER A 4-MONTH PERIOD. OF THESE, A TOTAL OF 35 MEN GAINED ADMISSION TO 5 DIFFERENT HALFWAY HOUSE FOLLOWING THEIR DISCHARGE FROM THE CENTERS. THESE 35 MEN COMPRISED THE SAMPLE IN THE PRESENT STUDY. A MATCHED CONTROL GROUPS OF 35 MEN WHO DID NOT ENTER HALFWAY HOUSES WAS DRAWN FROM THE REMAINING POPULATION OF MEN ADMITTED TO THE DETOXIFICATION CENTERS OVER THE SAME PERIOD. THE FIVE HALFWAY HOUSES TO WHICH THE MEN WERE REFERRED SHARED SEVERAL BASIC CHARACTERISTICS. INFORMALITY WAS EMPHASIZED IN A NONINSTITUTIONAL, HOMELIKE ATMOSPHERE. PARTICIPATION IN ALCOHOLICS ANONYMOUS MEETINGS WAS ENCOURAGED, AS WELL AS COOPERATION IN DOING HOUSEKEEPING AND MAINTENANCE CHORES. FULL-TIME EMPLOYMENT OUTSIDE THE HOUSE WAS STRESSED. A STAY OF 4 TO 8 MONTHS WAS EXPECTED. THE TOTAL FOLLOWUP GROUP OF 70 MEN WERE PREDOMINANTLY WHITE, BETWEEN 55 AND 60 YEARS OLD, WITH ABOUT 10 YEARS OF EDUCATION. MOST WERE NOT EMPLOYED AT THE TIME OF ADMISSION TO THE DETOXIFICATION CENTER. SIX PERCENT OF THE HALFWAY-HOUSE SAMPLE AND 37 PERCENT OF THE CONTROL SAMPLE HAD BEEN ARRESTED FOR DRUNKENNESS DURING THE FOLLOWUP PERIOD. HALF THE MEN IN THE HALFWAY-HOUSE SAMPLE WERE READMITTED TO A DETOXIFICATION UNIT DURING THE FOLLOWUP PERIOD COMPARED WITH ONLY 26 PERCENT OF CONTROLS. THE ANALYSES SHOWED A LACK OF EFFECTIVENESS OF HALFWAY HOUSES IN REDUCING DRUNKENNESS EPISODES FOLLOWING DISCHARGE. FOOTNOTES AND REFERENCES ARE PROVIDED. (PRG)