In an attempt to identify factors determining central venous catheter-related complications in newborns and infants, 587 cases have been retrospectively analyzed. Attention has been paid to the influence of the incidence of babies' body weight, site of insertion, and technique of placement of the catheter and the material used, ie, silicone (SI) or polyurethane (PU). Overall complications occurred in 28% of the catheters with 2 deaths due to cardiac tamponade. Mechanical complications happened in 22% of the catheters, including dislodgement (11.6%), extracorporeal perforation (5.3%), and obstruction (5%). Septic complications occurred in 4% catheters, including proven bacteriemia (2.5%), abscess at the entry site (1%), and isolated fever (0.8%). Clinically evident caval thrombosis occurred in 1% of the catheters. Overall complications were significantly higher when the body weight was lower than 2,500 g (P less than .01) due to a significantly higher incidence of septic complications (P less than .05). When a proximal site of placement of the catheter was used, both septic and mechanical complications were more frequent than in the distal approach (P less than .01). The incidence of complications was similar in surgically and in percutaneously placed catheters as in SI and PU catheters. Nevertheless, fatal complications occurred only in PU catheters, leading us to avoid the choice of such material in newborns and small infants.