People's beliefs about the origins of their health, sometimes referred to as health locus of control, have been shown to influence a variety of important behaviors, including the propensity to engage in effective health maintenance activities, and the willingness to seek and follow medical advice. The purpose of the present study was to explore the nature, i.e., the structure of the health locus of control beliefs, using the Multidimensional Health Locus of Control Scales. The sample size (609 college students) was sufficiently large to allow the use of confirmatory maximum-likelihood factor analyses. The robustness of construct validity findings across various matrices of inter-item association was also investigated. Results suggest that the development of larger and more diverse item pools measuring more constructs might be useful in further exploring the structure of health locus of control beliefs. Such item pools would allow the identification of more factors and better model fit than the model supported in this study, one with three factors (six items per factor) correlated with each other. An appendix lists the 18 scale items. (Contains 38 references and 6 tables.) (Author/SLD)