In a 3-year period 157 single lumen Broviac catheters were inserted in 145 children with various neoplastic diseases. The overall duration of the catheter courses was 30,533 days (median, 171; range, 2 to 647). Sixty-five percent of the catheter courses (102 of 157) were complicated by at least 1 febrile episode, for a total of 157 episodes. According to European Organization for Research on Treatment of Cancer criteria, 79 febrile episodes (50%) were classified as microbiologically documented infections, 57 (36%) with and 22 (14%) without septicemia; 31 (20%) as clinically documented infections; and 47 (30%) as possible infections. Of the 79 microbiologically documented infections 21 were catheter-related infections (CRI), 32 were catheter-unrelated infections and 26 were infections of unknown source. Only 48% of CRI occurred during neutropenia (less than 1000 neutrophils/mm3), compared with 88% of catheter-unrelated infections and 96% of infections of unknown origin (P = 0.00007). Gram-positive microorganisms (56% staphylococci) accounted for 78% of all isolates in CRI, 47% in catheter-unrelated infections and 43% in infections of unknown origins (P = 0.03). Fungi represented 12% of all isolates. Clinical and microbiologic resolution without removal of the catheter was achieved in 12 of 21 CRI (57%) and no patient died from a CRI. This study indicates that over 3 of 4 of CRI are caused by Gram-positive bacteria, occur in neutropenic and non-neutropenic patients (approximately 50%) and can be successfully treated without removing the catheter.