The dose-effect relation of nisoldipine in 3 single oral doses (5 mg, 10 mg, 20 mg) on exercise induced ST-segment depression, blood pressure and peripheral vascular response was evaluated in 16 patients with angiographically proven coronary artery disease and stable exertional myocardial in ischemia. The study was conducted according to a single-blind, randomized, placebo-controlled protocol with intraindividual cross-over. Maximal ST-segment depression and ischemia-score (ST-segment depression, workload time) under a constant submaximal workload exercise-protocol were analyzed with blood pressure, heart rate and the index b/a of digital pulse-plethysmography. 2 hours after medication nisoldipine led to a dose-dependent reduction of ST-segment depression by 12% (n.s.), 29% (p < 0.05) and 43% (p < 0.01), respectively. 8 hours after medication the ischemia-score decreased from 2.98 to 2.34 with the 20 mg-dose (p < 0.05). Systolic and diastolic blood pressure were reduced dose-dependent by 7%, 9%, and 14% with no change of heart rate at 2 h after medication. Digital pulse-plethysmography showed an acute reduction of the index b/a from 0.72 (placebo) to 0.63 (-12.5%, p < 0.01) with 10 mg and to 0.56 (-22%, p < 0.01) with 20 mg. Thus nisoldipine showed a dose-related antiischemic efficacy lasting for at least 8 h with the 20 mg dose. A small but significant peripheral vasodilatation 2 h after medication was observed.