Control of hypertension remains poor, and lack of adherence to medication is considered a primary reason. Few studies have examined the reasons for medication nonadherence in African American, lower-income, rural adults receiving medications at no personal cost. Moreover, our understanding of how the provider-patient relationship influences adherence in this population is limited. In this study, the authors (1) examined reasons for taking less medication than prescribed and (2) examined the association between provider-patient variables and medication adherence. A total of 434 participants (94.8% African American) were included. The most frequently endorsed reasons for taking less medication than prescribed were not having blood pressure medicine when it was time to take a dose (36%), running out of medicine (35%), bothered by side effects (29%), and a change in one's daily routine (27%). Nonadherent individuals were significantly more likely to report discomfort with asking the health provider questions (74% vs 63%), were more likely to report that health care visits were stressful (25% vs 16%), and exhibited more depressive symptoms (58% vs 45%). Adherent patients had lower blood pressure (systolic: 133±15.8 mm Hg vs 138±17.6 mm Hg, P value=002; diastolic: 80±9.8 mm Hg vs 83±11 mm Hg, P value=003) than individuals who were less adherent. Clinicians providing care to rural, poor hypertensive patients should routinely assess self-management behaviors, logistical barriers, and emotional health. Creating clinical encounters that minimize the stressful nature of the visit and encourage patient question-asking behavior may also be important for the optimal management of hypertension. © 2010 Wiley Periodicals, Inc.