1 The favourable haemodynamic effects of captopril in patients with congestive heart failure have been reported. 2 We have treated 25 patients with severe chronic congestive heart failure with captopril in doses of 75‐450 mg daily. Before entering the study all patients remained in New York Heart Association functional class IV despite high‐ dose diuretic and vasodilator therapy. 3 Mean cardiothoracic ratio was 60%, and all patients had a shortening fraction of 18% or less on echocardiography (normal 25 to 40%). 4 Five patients died within one month of captopril and five between four and seven months, three of whom had improved to class IIM and one to IIS before death. 5 Of the 15 survivors one was referred for a heart transplant when he had improved to class IIM. The remaining 14 patients were followed for 8‐16 months. Ten improved to New York Heart Association class I or IIS and four to class IIM or III. Diuretic requirements were decreased considerably in all 14. Side effects were common but captopril did not have to be withdrawn. Captopril is a highly effective drug in the treatment of patients with congestive heart failure refractory to currently accepted therapy.