The effects of the second generation calcium channel blocking drug nisoldipine on subjective and objective measurements of exercise performance were studied in 19 patients with moderate to severe heart failure (9 New York Heart Association functional class 2, 9 class 3 and 1 class 4) due to fixed ventricular dysfunction following myocardial infarction. Nisoldipine (10 mg 3 times daily) or placebo were administered for 8 weeks in a double-blind parallel study, assessing exercise performance by symptom-limited treadmill exercise testing using a modified Naughton protocol. Nisoldipine was well-tolerated and produced a small increase in peak estimated workload performed (6.2 ± 2.9 to 8.2 ± 3.0 METs, p = 0.06). The rate of perceived exertion (Borg scale) increased from 17.5 ± 2.2 to 18.8 ± 1.2 (p < 0.02). The higher workload was performed at a lower peak systolic blood pressure (p = 0.03), higher peak heart rate (p = 0.06) and identical double product (NS). There was no change in resting and peak heart rate and blood pressure or in exercise performance in patients receiving placebo. Resting left ventricular ejection fraction, measured by radionuclide ventriculography, was unchanged after 8 weeks both in the placebo (21 ± 9 to 20 ± 9%) and nisoldipine (34 ± 17 to 36 ± 19%) groups.