Objective: This study examined parental and professional beliefs about the efficacy of various treatment strategies for ADHD. Method: Parents of children with and without ADHD and seven medical and nonmedical professional groups (N = 673) completed a questionnaire examining their beliefs about the efficacy of various treatment regimes. Results: Principle component analysis identified four factors--school-based interventions, medical and allied health interventions, parent interventions, and nontraditional interventions. Although there were some group differences in the level of endorsement for these factors, there was a high degree of concordance between the groups. The school-based interventions factor was the most highly endorsed, whereas the nontraditional interventions factor was the least endorsed by the sample as a whole. Conclusion: The results suggest that the low level of interdisciplinary interaction that has been reported in the literature is not due to differences in beliefs about the efficacy of various treatment strategies for ADHD. (Contains 2 tables.)