BACKGROUND: Hypertension is extremely prevalent in patients with diabetes. Limited data exist on whether patterns of antihypertensive use in this population are consistent with evidence-based practice guidelines. OBJECTIVE: To evaluate utilization patterns of antihypertensive agents and blood pressure (BP) control among diabetic patients with hypertension. DESIGN. Retrospective cohort study. PATIENTS/PARTICIPANTS: In all, 9,975 patients with diabetes and hypertension as of March 2001 from an outpatient medical center of the Department of Veterans Affairs. MEASURES: Proportions of use of 6 different antihypertensive drug classes were compared for all patients receiving 1, 2, 3, or 4 or more drugs, and separately among patients with and without coronary artery disease (CAD). Blood pressure control (< 130/85 mmHg) was compared for untreated patients, those on monotherapy, and patients on multidrug regimens. RESULTS: Over 60% of patients were receiving angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blocker (ARB), followed by diuretics (38.1%), calcium channel blockers (35.3%) and beta-blockers (28.5%) with 19.1% of patients untreated. Patients on monotherapy were mostly receiving ACEI/ARB (59.5%). The majority (70.7%) of treated patients were on mulddrug regimens. In patients with CAD, beta-blocker and ACEI/ARB use was higher, and 70.5% of patients on single-drug regimens received either ACEI/ARB or beta-blockers. The proportions of patients not on medications, on monotherapy, or mulddrug regimens achieving BP control were 23.4%, 27.4%, and 24.9%, respectively. CONCLUSIONS: Patterns of anti-hypertensive therapy were generally consistent with evidence-based practice guidelines. Areas of improvement include increasing ACEI/ARB and diuretic use, decreasing the number of untreated patients, and increasing the proportion of patients with controlled BP in this population.