Pharmacokinetic studies of Trandolapril (2 mg), Benazepril (5 mg) and Quinapril (20 mg), marketed abroad was carried out on eight healthy male volunteers. Plasma samples were analysed by using indirect method of Angiotensin I radioimmunoassay method (RIA). Pharmacokinetic parameters such as Cmax, T(max), T1 /2, Kel and AUC were determined and subjected to statistical analysis. During the study, no undesirable side effects were observed in any of the volunteers.