Ca2+-antagonists have a vasodilatory action which makes them useful in treatment of congestive heart failure (CHF). Nicardipine (N) has potent vasodilatory properties. Fifteen patients, mean age 62 years, with CHF, in class II-III, despite previous therapy, were studied. The individual optimal dose of N was titrated from 20 mg t.i.d. to 40 mg t.i.d. Treatment continued for 6 weeks. Weight, left and right ankle circumference, heart rate (HR), and blood pressure (BP) were recorded. Exercise test using a bicycle ergometer, chest x-rays calculating cardiac size in ml/m2 BSA, 24-hour continuous ECG monitoring and left ventricular ejection fraction (LVEF) were performed before and after treatment. Two patients responded to 20 mg t.i.d., 7 to 30 mg t.i.d. and 6 to 40 mg t.i.d. Two patients responded poorly to treatment. Mean weight decreased significantly from 87 to 78 kg (p < 0.001). Both ankle circumferences dropped significantly (p < 0.001) with a decrease of more than 4 cm. LVEF increased in 13 patients and cardiac size decreased. Maximum exercise time increased in 13 patients from 3 to 9 minutes (p < 0.001) and the total workload in these patients increased significantly (p < 0.001). Two patients did not show changes in weight, LVEF, cardiac size or ankle circumference. The NYHA classification did not change in these two while it improved in the other 13. No serious side effects were seen. Nicardipine was an effective treatment in congestive heart failure. These results indicate that Ca2+-antagonists with vasodilating properties can be used when treating patients with CHF, especially if the underlying pathology is coronary artery disease.