Anti-ischemic effect of angiotensin-converting enzyme inhibitor--chinapril was examined by exercise tolerance test [ETT] in randomised, cross-over double blind comparison in 20 pts with coronary artery disease treated with beta-blockers and nitrates. After 8 weeks of chinapril treatment maximal work capacity and exercise duration were significantly greater in comparison with baseline values, respectively: 7,8 vs 6,7 METs (p < 0,05) and 416 vs 335 s (p < 0,05). Time to ST segment depression was significantly longer after chinapril treatment: 394 vs 298 s (placebo) p = 0,01) vs 277 s (baseline), p = 0,008. The number of patients with exercise ST depression was significantly lower (63% vs 100%). Rate pressure product wasn't changed after chinapril treatment. Vitamin C therapy did not have influence on ischemia signs in exercise tolerance test.