The clinics located in Maryland, New Jersey, New York, Connecticut, Hawaii, and Washington State offered methadone maintenance, detoxification, abstinence, naltrexone treatment, and abstinence counseling. Of the 897 subjects selected from admission to the clinics, 64.8 percent were male, 35.2 percent were female, 49.6 percent were white, 37.7 percent were black, 11.6 percent were Hispanic, and 1.1 percent were 'other.' A 29-item questionnaire administered to the subjects covered problem areas such as narcotic drugs, other drugs, alcohol, physical, psychological, family, money, and legal difficulties. Opinions with respect to appropriate treatment services also were included in the questionnaire. Counselors were given a 21-item questionnaire designed to assess treatment outcome 6 months following client admission. Results indicated that relationships between client-counselor congruence as measured by three major content domains of the questionnaire, and treatment outcome, assessed by counselor ratings of client progress, varied among ethnic/sex groups of addicts. Blacks and Hispanics, particularly black females, generally showed the greatest association between congruence and outcome. Among whites, males showed the least. Although these congruence/outcome relationships were slight, the need for tailoring treatment according to ethnic/sex classifications of addicts is suggested. Issues relating to the predictive utility of congruence as a measure of treatment outcome are discussed. Tabular data and 24 references. (Author abstract modified)