In a 8-week double-blind clinical study in 32 patients with chronic heart failure, the efficacy of an additional therapy with nisoldipine (5 mg/b.i.d.) was examined in comparison to placebo. In the second part of the study all patients were given 2 x 5-10 mg nisoldipine until the total duration of treatment was 24 weeks. After 8 weeks exercise-tolerance under nisoldipine had significantly improved compared with placebo. At the same time clinical symptoms improved markedly. Nisoldipine is a suitable adjunctive drug for treatment of chronic heart failure, particulary in those cases due to coronary heart disease.