Aims. A multicentre, double-blind, placebo-controlled trial was conducted in 542 patients, randomized 7-10 days after myocardial infarction, to study the effect of nisoldipine coat-core (nisoldipine-CC) on exercise after 6 months. Secondary endpoints included exercise-induced ischaemia, left ventricular function measured by Doppler echocardiography, adverse cardiac events and clinical outcome. Methods and results. Patients had reduced left ventricular ejection fraction between 25 and 50%, but no heart failure. Exercise time was not different in the two groups. Nisoldipine-CC prolonged time to 1 mm ST deviation (P = 003). There was an effect of nisoldipine-CC of +3.6 cm.s-1 early peak velocity (P = 0.01) and of - 6.2 ms on isovolumic relaxation time (P = 0.005), but no effects on left ventricular volumes or ejection fraction. There was a trend towards reduced mortality (one death in the nisoldipine-CC group vs seven in the placebo group, P < 0.07) and the combined end-point of mortality and cardiac events (P = 0.09). Peripheral oedema occurred in 49 patients assigned to nisoldipine-CC and two assigned to placebo (P < 0.001). There were no differences in non-cardiac events. Conclusions. Nisoldipine-CC did not improve exercise time but increased time to 1 mm ST deviation, and improved diastolic left ventricular function. It is safe and well tolerated in post-infarction patients with impaired left ventricular function.