The literature on combined treatment has suggested that the attitudes of staff members toward combining treatment for drug and alcohol abusers are important determinants of its success. A survey measuring attitudes thought relevant to the issues of combined treatment was mailed to treatment staff from a nationwide sample of drug, alcohol, and combined treatment agencies. Results indicated that combined treatment staff had more favorable attitudes toward combined treatment than did drug or alcohol staff, and that significant differences existed in the attitudes of drug, alcohol, and combined staff toward drug and alcohol abusers. In addition, it was found that staff background and attitudes toward drug and alcohol abusers were significantly related to attitudes toward combined treatment. Treatment staff who worked at combined treatment agencies and were White were likely to have favorable attitudes toward combined treatment. In terms of attitudes toward drug or alcohol abusers, it was found that staff members who held unfavorable stereotypes or moral views about drug or alcohol abusers tended to be opposed to combined treatment. These empirical results support clinical impressions of combined treatment advocates as reported in the literature. The results are discussed in terms of the relevance of staff attitudes for the effectiveness of combined treatment and for agencies which are considering the initiation of combined treatment.