Pretreatment and posttreatment Alcoholics Anonymous (AA) affiliation was investigated in respect to treatment outcome, demographic variables, and psychometric variables for 173 consecutive admissions to a residential behaviorally oriented, multimodal treatment program. Few variables were found to distinguish clients who chose to affiliate with AA following treatment from those who did not. However, AA attenders tended to report a higher incidence of and more severe alcohol-related problems prior to treatment. Pretreatment AA affiliation was not found to influence prognosis significantly. However, an infrequent or irregular pattern of posttreatment AA attendance was associated with a much poorer prognosis than either regular attendance or nonattendance. Success:failure ratios were statistically equivalent for the latter two groups. It is suggested that the poor outcome evident among the infrequent attenders may be the result of“misaffiliation”or incomplete affiliation with the fellowship and/or the presence of a problem which supersedes the alcohol abuse.