Context: Diabetes care is challenging in rural areas. Research has shown that the utilization of electronic patient registries improves care; however, improvements generally have been described in combination with other ongoing interventions. The level of basic registry utilization sufficient for positive change is unknown. Purpose: The goal of the current study was to examine differential effects of basic registry utilization on diabetes care processes and clinical outcomes according to level of registry use in a rural setting. Methods: Patients with diabetes (N = 661) from 6 Federally Qualified Health Centers in rural West Virginia were entered into an electronic patient registry. Data from pre- and post-registry were compared among 3 treatment and control groups that had different levels of registry utilization: low, medium, or high (for example, variations in the use of registry-generated progress notes examined at the point-of-care and in the accuracy of registry-generated summary reports to track patients' care). Data included care processes (annual exams, screens to promote wellness, education, and self-management goal-setting) and clinical outcomes (HbA1c, LDL, HDL, cholesterol, triglycerides, blood pressure). Findings: The registry assisted in significantly improving 12 of 13 care processes and 3 of 6 clinical outcomes (HbA1c, LDL, cholesterol) for patients exposed to at least medium levels of registry utilization, but not for the controls. For example, the percent of patients who had received an annual eye exam at follow-up was 11%, 34%, and 38% for the low, medium, and high utilization groups, respectively; only the latter groups improved. Conclusions: As an initial step to achieving control of diabetes, basic registry utilization may be sufficient to drive improvements in provider-patient care processes and in patient outcomes in rural clinics with few resources.