To examine blood pressure control and prescribing practices in the treatment of hypertension, including the use of sample medications, in rural populations. Retrospective chart review of 296 hypertensive patients and surveys of primary care providers serving these patients. Twenty-seven rural, primary care clinics in North Carolina. Blood pressure control, with the practice site as the unit of analysis. An average of 29% of patients per clinic had blood pressures that were inadequately controlled. Wide variations existed between clinics in blood pressure control and medication costs. Thirty-two percent of all blood pressure medications used were either angiotensin converting enzyme inhibitors or calcium channel blockers compared with 26% use of diuretics. Virtually all clinics used sample antihypertensive agents and reported that sample medications were an important source of free medications for their indigent patients. Reported sample use by practice was positively correlated with the mean daily hypertensive medication costs. Variations in blood pressure control were not explained by any measured variables, although the sample size was small. Large variations exist within rural North Carolina primary care clinics in blood pressure control and medication costs. We need to study further the relationships of new antihypertensive agents, medication costs, and sample use with blood pressure control, health care costs, and other patient outcomes.