Serum levels of interleukin-1 beta (IL-1β), soluble interleukin 2 receptors (sIL-2R), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-α) were measured to predict some characteristics of febrile episodes in children with cancer and neutropenia. Forty-eight episodes of febrile neutropenia were determined in 23 pediatric cancer patients, including 35 febrile episodes without identifiable source, 7 episodes of bacteremia due to Gram-negative organisms and 4 due to Gram-positive organisms, and 2 fungal infections. Interleukin-6, sIL-2R, and IL-8 levels were significantly higher at the beginning of the febrile episodes than those of controls (p<0.001, p<0.001, and p<0.001). Interleukin-6, sIL-2R, and IL-8 levels were higher in patients with bacteremia due to Gram-negative organisms than in those with Gram-positive ones (p=0.042, p=0.006, and p=0.023, respectively). TNF-α and IL-1β levels were similar in febrile episodes and controls (p>0.05). In conclusion, sIL-2R, IL-6, and IL-8 levels may be helpful in the prediction of infection in febrile cancer patients with neutropenia and measurements of IL-1β and TNF-α were not useful for identifying the presence and the type of infection in febrile neutropenic episodes in children.