Abstract: ACE inhibitors (ACEi) are widely recommended and used for treatment of hypertension. There are number of ACEi to choose from. It make sense to use the one that that has been shown to be most effective in prevention of serious hypertension complication such as stroke. If there is more that one choice it make sense to use the one with lower acquisition cost. In this paper we are looking into the evidence for using ACEi as a first line treatment for hypertension and to try and find out which ACEi has been associated with the best clinical outcome. We found no long-term trials comparing ACEi and placebo for treatment of hypertension. We found no head-to-head studies directly comparing the main four ACEi’s, commonly prescribed in England. On the basis of the evidence presented, lisinopril is the only commonly used ACEi that can be considered a first line treatment for hypertension. There is some evidence for ramipril, although this is not as strong. There is no substantial evidence of the effectiveness of enalapril and in the presence of a proven treatment (lisinopril) it makes no sense to use it for the treatment of hypertension. There is no evidence that perindopril improves mortality or stroke rate in patients with hypertension. Perindopril is no better than placebo for treatment of patients with previous TIA or stroke.