Problems in compliance with treatment and illness management have frequently been traced to differences between patients' explanatory models of illness and the biomedical model. We investigated the relationship of cultural beliefs about hypertension to compliance with treatment. Using semistructured interviews, we elicited the explanatory models of hypertension held by 60 black hypertensive women being treated at Charity Hospital in New Orleans. The patient sample was followed for 2 months to obtain data on compliance with antihypertensive treatment and blood pressure control. As described, 53% of the patient sample recognized two basic folk illness models: "high blood" and "high-pertension." Patients' illness models were significantly related to compliance with treatment at the P = .01 and .001 levels. Compliance was related to blood pressure control at the P = .05 level. These results indicate that culturally influenced health beliefs are an important influence on compliance and, in turn, blood pressure control. Improved understanding of these problems by physicians may improve the management of their patients' illness.