In view of an apparent increase of central venous catheter-related infections among our bone marrow transplant (BMT) patients, a retrospective study of infectious complications of central venous catheters was conducted. During 1992, 147 central venous catheters were placed in 133 patients. The overall infection rate of all catheters was 3.3 per thousand catheter-days (bacteremia 1.8, site infection 1.5). Patients scheduled for BMT had the highest infection rate of 11.5 (bacteremia 6.7, site infection 4.8). HIV patients had an infection rate of 6.6 per thousand catheter-days (bacteremia 3.8 and site infection 2.8) and patients with other diagnoses had a rate of 2.4 (bacteremia 1.3 and site infection 1.1). The difference of infection risk among the three groups is statistically significant (logrank p < .0001). In analyzing the 11 BMT patients more carefully, 14 catheters were placed. Of these, 9 catheters were removed, 8 (89%) of which were secondary to infection. Multivariate analysis showed that patients under 50 and BMT patients were more likely to develop catheter-related infection. While the cause of this complication is not known at present, the possible association with PBSC harvest is of much concern.