Adriamycin (Adriablastine), administered weekly at the dose of 5 mg/kg i.p. for 3 weeks in rats, produced a general decrease of vitality associated with a decrease of body weight, hypothermia, decreases of stroke volume and cardiac output. Hematocrit was decreased. Renal blood flow decreased whereas pulmonary blood flow increased. Mean blood pressure and heart rate remained unaffected. Biochemical evaluations revealed a decrease of blood urea and serum creatinine, which might be related to decreased food intake and protein metabolism. Morphological changes in the heart tissue could not be appreciated. Venoruton (HR), administered at the dose of 300 mg/kg p.o. daily for 28 days (5 days before and 23 days after the first injection of adriamycin), improved adriamycin-induced clinical signs and symptoms (loss of body weight, hypothermia and decreased general vitality). It tended to increase cardiac output and stroke volume.