OBJECTIVES: This study compared blood pressure (BP) outcomes (changes in BP and goal attainment) in adult patients (age >18 years) treated with an ARB or ARB-HCTZ fixed dose combination. METHODS: A retrospective study was conducted using the GE Centricity EMR database, which contains the ambulatory health records for more than 11 million US patients. Patients with a physician order for one of the following ARBs or fixed-dose combination (FDC) with HCTZ (candesartan, irbesartan, losartan, olmesartan or valsartan) prior to December 2007 were included in the study. Demographics, clinical characteristics (co-morbidities, previous antihypertensive medications) and BP readings at baseline and throughout the 13-month follow-up period were recorded. The mean change in systolic and diastolic BPs and percent patients attaining BP goal (two consecutive BP readings <140/90 or 130/80 in patients with diabetes or renal disease) were recorded. RESULTS: A total of 81,706 patients (60.5% female, mean age 61.6 years) receiving an ARB or ARB-HCTZ FDC were identified. Patients with prior antihypertensive medication usage [57,501 (70.4%)] had higher baseline BP readings [mean SBP (SD): 147.4 (29.35) vs. 138.7 (18.93) mmHg; mean DBP (SD): 84.2 (17.93) vs. 80.8 (12.35)] and also experienced greater reductions in BP [mean SBP change (SD): 21.1 (29.61) vs. 13.2 (17.31) mmHg]. At baseline, a greater proportion of patients with prior antihypertensive medication usage (57.8% vs. 49.5) were not at BP goal. BP goal attainment was similar between the two groups (60.6% vs. 62.6%, prior vs. absence, respectively). Mean time to goal (82.8 days vs. 78.5 days, prior vs. absence, respectively) was also similar between the two groups. CONCLUSIONS: Most patients initiating ARB /ARB-HCTZ therapy have utilized other antihypertensive medications in the 13 months prior to starting ARBs. Prior antihypertensive medication users experienced greater reductions in BP. BP goal attainment was similar between patients with and without prior antihypertensive medications.