The authors report the case of a 49 year old woman who presented with congestive cardiac failure and hypertension. Clinical examination revealed a high output state and an abdominal mass with a continuous murmur which angiography showed to be a very vascular right renal tumour with a large and early venous return. Catheter studies confirmed the increased cardiac output (cardiac index 5.37 l/mn/m2), an increase in right heart and mean pulmonary capillary pressures (28 mmHg), decreased peripheral arterial resistances and a left-to-right shunt effect at the level of the suprarenal inferior vena cava (+ 3.8 volumes of oxygen per 100 ml). After radical right nephrectomy, the cardiac failure and hypertension regressed and the haemodynamic parameters returned to normal.