In order to assess the effect of felodipine, a new calcium antagonist with vascular selectivity, on regional blood flow distribution at rest in chronic congestive heart failure, ten patients were studied during an acute test. Right heart catheterization allowed the evaluation of hemodynamic parameters; renal blood flow was calculated using paraamino-hippuric acid clearance; hepatic blood flow measurement was based on indocyanine green clearance; and limb blood flow was assessed with venous occlusion plethysmography. Blood samples were collected for the analysis of plasma catecholamines, renin, and aldosterone. All parameters were recorded in duplicate under basal conditions and after felodipine infusion. The infusion of felodipine induced a significant increase in cardiac index, stroke work index, and limb blood flow. Systemic and pulmonary arterial blood pressure, pulmonary wedge pressure, and systemic resistance underwent a significant decrease. The heart rate, pulmonary resistance, renal blood flow, and hepatic blood flow were not changed. In conclusion, felodipine was of benefit in congestive heart failure at rest in an acute test, acting through a marked decrease in vascular resistance and a consequent improvement in cardiac output and limb blood flow. No changes in renal and hepatic blood flow were observed.