OBJECTIVES: The aim of this study was to review randomized controlled trials (RCTs) comparing Valsartan 20/40/80mg, Telmisartan 80/160mg, Losartan 50/100mg and Irbesartan 75/150mg at starting doses. A literature review of ARBs has not been previously performed. METHODS: Published literature was reviewed using OVID Medline, Embase, PubMed and Cochrane databases, cut-off date June 8th, 2006, as sources of data and the abstracted data were recorded into structured forms. The quality of selected studies was assessed by CRD Report No 4, University of York. Search terms included “mild hypertension”, “moderate hypertension”, “anti-hypertensive agents” and others combined with the specific drug terms. Studies included were either “head-to-head” trials or randomized, double-blind or open label placebo-controlled trials (RCTs). Clinical measurement of blood pressure included not only ambulatory blood pressure monitoring (ABPM), but cuff BP and sphygmomanometer also. Patient population was defined as mild-to-moderate hypertension with no concomitant diseases. RESULTS: Forty-seven studies were included in the analysis. Duration of treatment was typically 8 to 12 weeks. Sample size ranged between 25 and 14820 patients. Mean age of sample ranged between 47 and 63 years. Of the selected literature, 29 studies were head-to-head trials, 20 were RCTs versus placebo and 8 were dose-response trials of the regimen. With respect to BP measurements, 14 studies used ABPM in contrast to 25 that used clinic BP. The remaining 8 reported both. With respect to study design 3 studies were meta-analyses, 25 were double-blind RCTs, 1 was a single-blind single-arm trial and 11 were open-label studies. 11 studies included either forced or elective titration. Finally, from the sample, irbesartan had the less retrieval, given that it is the newer agent of all. CONCLUSION: All studies complied with the CRD Report No 4 quality assessment criteria, University of York. The literature review was performed to be used for meta-analytic purposes.