Rates of infections and catheter complications in children with right atrial catheters (RACs) receiving chemotherapy were compared with those without RACs in a retrospective cohort study. One hundred sixty-five children presenting to Yale-New Haven Hospital with a malignancy diagnosed between January 1, 1981 and December 31, 1985 were followed through June 30, 1986 for the number of treatment-related complications resulting in hospitalization. The time on therapy totaled 80,089 person-days that were divided into 510 periods of observation defined by the presence or absence of a RAC, disease status (remission, partial remission, or relapse), intensity of chemotherapy (using a 0 to 4 scale), and use of radiation therapy. Children with RACs experienced markedly higher rates of sepsis (14-fold higher, P less than .0001) and catheter-site infection or other catheter complications requiring hospitalization (both greater than 30-fold higher, P less than .0001). These effects persisted after controlling for other risk factors, ie, disease status, chemotherapy intensity, and age. Children with RACs also had higher rates of fever and neutropenia and other infections requiring hospitalization that were more strongly influenced by the other risk factors. The association of RACs with sepsis, fever and neutropenia, and days hospitalized for treatment-related complications was assessed using multivariable analysis methods to control for disease status, intensity of chemotherapy, radiation therapy, type of cancer, age, and sex. The presence of a RAC (rate ratio [RR], 6.39; P less than .0001) and the disease status (RR, 2.45; P = .0004) were the only factors that predicted sepsis. Fever and neutropenia rates were most influenced by chemotherapy intensity (RR, 2.31; P = .0001) and age (RR, 0.94; P = .013 per year of age) and less by the presence of a RAC (RR, 1.56; P = .053). Controlling for other risk factors, children with RACs experienced a 6.4-times higher rate of sepsis and spent an average of 15.4 more days per year in the hospital for treatment-related complications.