Decision analysis is applied to the group of angiotensin-converting enzyme inhibitors, in order to select those which should be included in the hospital formulary and to establish a research method which allows the reproduction of the process with new, related drugs. Captopril enalapril and lisinopril were the alternatives considered. Evaluation criteria were efficacy, clinical experience, safety, dosage interval, hepatic bioactivation, interactions, dosage forms and cost. A relative weight was assigned through a survey among the hospital's staff. Each alternative was evaluated in relation to all criteria. Sensitivity analysis was applied to validate the method. Enalapril obtained the highest score, followed by lisinopril and captopril. The sensitivity analysis confirms this result. Enalapril is selected for the hospital formulary due to its higher score, although the differences between the three are very small.