4,800 psychologists, psychiatrists, and social workers were surveyed (return rate = 49%) to examine attitudes and practices regarding dual professional roles, social involvements, financial involvements, and incidental involvements. Half of the Ss rated the degree to which each behavior was ethical; the other half reported how often they engaged in each behavior. A majority believed dual role behaviors to be unethical under most conditions; most reported that they had rarely or never engaged in the behaviors. 10 factors (therapist gender, profession, age, experience, marital status, region of residence, client gender, practice setting, theoretical orientation, and practice locale) were examined for their relation to beliefs and behaviors. A higher proportion of male than of female therapists were perpetrators of sexual and nonsexual dual relationships. The professions did not differ among themselves in terms of (a) sexual intimacies with clients before or after termination, (b) nonsexual dual professional roles, (c) social involvements, or (d) financial involvements with patients. 10 specific training implications are discussed in light of the exploitive and clinically harmful nature of dual relationships.