The success rate, frequency of complications and changes in systolic arterial pressure and heart rate during percutaneous pulmonary artery catheterization via an antecubital vein were evaluated before induction of anaesthesia in 84 patients about to undergo cardiac surgery. Serious complications were angina (2%) and a small tear in the tricuspid valve (one patient). If one of the basilic veins was used, the success rate was 93%. When it was necessary to use a cephalic vein, the success rate decreased to 60%. Overall success rate was 75%. Placing the catheter in the pulmonary artery resulted in an immediate increase in systolic arterial pressure in all patients and a significant increase in heart rate in patients not taking beta-adrenergic blocking drugs. This study demonstrates that percutaneous catheterization of the pulmonary artery via the basilic vein is a simple, safe, effective technique associated with few complications.