25 patients are presented with chronic cardiomyopathy (NYHA class IV), who were refractory to conventional digitalis and diuretics treatment which was administered over at least 3 weeks. The patients were split in 2 groups: the first group consisted of 10 patients who were haemodynamically monitored while being administered nitroprusside for 24 hours. After the treatment, the cardiac index significantly increased (by 36%), left ventricular filling pressure decreased (by 48%), and systemic vascular resistance fell (by 47%). The second group, consisting of 15 patients, was administered prazosin in addition to conventional treatment. The effects of prazosin were clinically monitored. After 3 weeks of continual prazosin treatment, the clinical condition of 12 patients was improved to NYHA class II whereas the condition of the other 3 was improved only to NYHA class III. During further treatment this improvement was maintained. The effects of the treatment can be easily followed and assessed on the basis of clinical features, so that other, more complex methods of follow-up are not required. The results of our study show that patients with refractory heart failure can be safely administered prazosin without previous assessment of haemodynamic parameters.