OBJECTIVES:   To explore the effectiveness of combination regimens containing Angiotensin Receptor Blockers (ARBs) compared to those containing ACE Inhibitors (ACEIs) in reaching target blood pressure (BP) in a real-world setting.METHODS:   Records from a longitudinal population-based database of more than 170,000 patients in over 53 family practice clinics in southwestern Ontario, Canada were analyzed.  These records contained chart-abstracted information such as visit diagnosis, BP, medications and consultation notes.  The records from adult non-diabetic patients who were diagnosed with hypertension and were initiated on combination therapy in 2005 and continued on the combination for at least 9 months were included.  Hypertension was defined as a BP exceeding 140/90 mmHg, chart entry of a diagnosis of hypertension, or use of anti-hypertensive medication.  The proportions of patients reaching target BP (BP less than 140/90 mmHg) were recorded. Due to the well known comparable safety profile of the compounds, a safety analysis was not performed. RESULTS:   A total of 6160 patients were treated with dual combinations containing an ARB or an ACEI. In patients treated with at least one ARB, 39% reached target BP compared to 31% of those not treated with an ARB (p=0.004).  When comparing combinations with HCTZ, 35% and 30% of those on ARB and ACEI, respectively, reached target BP (p=0.006).  Within the patients treated with an ARB either in dual or tri-therapy, 48% of patients irbesartan reached target BP when the ARB was irbesartan compared to 42% for losartan or valsartan (p=0.001 for both), and 41% for candesartan (p=0.001). CONCLUSIONS:   In a real-world setting, a greater proportion of hypertensive patients treated with a combination containing an ARB reached target BP than those treated with a combination not containing an ARB.  Within the ARB class, a greater proportion of patients treated with a combination containing irbesartan reached target BP.