Seven newborn infants (birth weight 920 to 1,900 g) who developed pulmonary oedema as a complication of the use of percutaneous silastic central venous catheters are described. Clinical symptoms occurred three to forty days after catheter placement. In each case, radiographic detection, performed by the injection of radiopaque dye, localized the tip of the catheter in the pulmonary artery or in its collateral branches. Clinical symptoms decreased after catheter replacement in the right atrium. The casistic examination allows the Authors to suggest some aetiopathogenetic hypothesis.