OBJECTIVE To prospectively determine risk factors for bacteremia in febrile neutropenic children with malignancies. METHODS We studied 199 episodes of febrile neutropenia in 80 children with malignancies, treated by conventional chemotherapy for a 4-year period (2000 - 2004). A standardized computer database with a set of variables for each febrile neutropenic episode was used. C-reactive protein (CRP) was measured at the first febrile episode and on the 3rd and 5th day from the beginning of antibiotic therapy by immunoturbidimetric method. Blood cultures were taken at the onset of fever and before initiation of antibiotic therapy. RESULTS Multivariate logistic regression analysis determined 5 variables as independent risk factors for bacteremia: the underlying malignant disease (leukemia, non - Hodgkin's lymphoma / NHL, stage IV), chills, perianal cellulitis, presence of central venous catheter and CRP rise >or=34.5 mg/L between the onset of fever and the 3rd day of empiric antibiotic therapy. Thus we identified a low-risk group for bacteremia of 19.1%. CONCLUSIONS Serial measurement of CRP allows for definite risk stratification of febrile neutropenic episodes on the 3rd day from the onset of fever. The low-risk group could be eligible for sequential empiric antibiotic therapy.