Earlier research had demonstrated that alcoholics with attention deficit disorder residual type (ADDRT) differ from other alcoholics on the Minnesota Multiphasic Personality Inventory (MMPI). The purpose of this study was to explore the influence of drug abuse on the relationship of ADDRT and alcoholism as reflected on the MMPI. Groups of 48 male alcoholics, 28 ADDRT alcoholics, 25 ADDRT alcohol and drug abusers and 18 alcohol and drug abusers were all administered the MMPI. Significant differences were found between the alcoholic and ADDRT alcoholic groups on scales Pd, Sc, Si, F, and K. For the ADDRT alcohol and drug abusers versus the alcohol and drug abuser groups, they differed on scales K, Hs, D, Pd, Pa, Pt, Sc, Si, F, K, and L.