Changes in blood test values from the time of discharge from an alcohol treatment program to 3-month follow-up were studied in two consecutive series of alcoholic men. The parallel combination of a percent increase in gamma-glutamyltransferase (GGT) of greater than or equal to 20%, in aspartate aminotransferase (SGOT) of greater than or equal to 40%, and in alanine aminotransferase (SGPT) of greater than or equal to 20% over discharge values was developed as a rule and then cross-validated to identify those alcoholic men who had resumed drinking at follow-up. Serial determination of these three test values in combination can be used to distinguish recovering alcoholics who remain abstinent from those who resume drinking.