People might be attracted to and use complementary and alternative medicines (CAM) because they hold beliefs that are congruent with CAM. This article collates, examines and synthesizes the evidence surrounding this hypothesis. Most studies are cross-sectional and focus on a limited number of beliefs. Multivariate studies suggest that beliefs related to control and participation, perceptions of illness, holism and natural treatments, and general philosophies of life predict CAM use when controlling for demographic and clinical factors. Further research should examine the robustness of these relationships in different illness groups and the prospective relationships among beliefs and CAM use over time.