During a 26-month period, 158 central venous catheters were inserted in 114 children (median age: 4.5 years) with malignant diseases. Polyurethane catheters were used, inserted either using a cut-down procedure or percutaneously in the external or internal jugular vein. All catheters were tunnelled from the point of insertion to the midpoint of the manubrium or upper sternum. The catheter tip reached the superior caval vein or the right atrium in 94% of the cases. The catheters were used for all infusions, including total parenteral nutrition, and for blood sampling. The median catheter duration was 104 days (range 5-835 days). Sixty-eight (43%) of the catheters were removed as they were no longer needed, and 31 (20%) were removed due to local infection or septicaemia. During a total of 23,486 catheter days (64.4 years), 110 episodes of septicaemia occurred. This represents one episode per 214 catheter days. In 43 of the 110 episodes of septicaemia, blood cultures showed growth of bacteria of the kind usually found in the gastrointestinal and respiratory tracts. All septicaemias were treated with intravenous broad-spectrum antibiotics and in 21 cases the catheters were removed due to septicaemia. Thirty-four (22%) catheters were removed accidentally. There were two cases of subclavian vein thrombosis.