Attitudes of opioid users toward methadone maintenance were studied using semi-structured field interviews. One hundred and sixty-one heroin and speedball users in San Antonio, Texas, were interviewed between 1989 and 1992. Users were classified according to whether or not they had ever been on methadone maintenance. Opioid users who had never been on methadone maintenance were more likely to express a negative attitude toward methadone maintenance than users who had been on it (50% versus 30%). Sources of negative attitudes fell into the following categories: (1) general societal disapproval of addictive drugs, including methadone; (2) prior experience with 12 Step groups or abstinence-based treatment programs; (3) previous forced rapid detoxification from methadone in jail; and (4) observation of methadone maintained peers who continued to use drugs. Very few respondents reported adverse effects from methadone itself as a source of negative attitudes. Sources of positive attitudes included: (1) prior successful treatment with methadone; and (2) observation of methadone patients who stopped using drugs.