The aim of this study was to evaluate the anti-ischemic efficacy of 2 different doses of benazepril (B), a new ACE-inhibitor, 10 and 20 mg, given per os. Fifteen male patients gave informed, written consent; they were aged 40-67 years, with stable effort angina pectoris and were randomly given, in double-blind condition, a tablet containing B 10 mg, B 20 mg or placebo (PL), once a day, according to a 3 x 3 latin square design. Bicycle exercise tests were performed on the same day, 2 and 10 hours after the last drug intake. B 10 mg and B 20 mg, in patients with stable effort angina, compared to placebo, increased ischemic threshold and decreased ischemic ST depression at maximal work, after 2 hours but not after 10 hours. In conclusion B 10 mg and B 20 mg showed anti-ischemic activity 2 hours after drug intake.