Status of iron nutrition along with demographic, anthropometric, dietary, and biochemical parameters were recorded in 98 pediatric cancer patients at the time of referral. Dietary intake in each patient was analyzed for calories, protein, and iron. Blood specimens were analyzed for hemoglobin (Hgb), hematocrit (Hct), iron, total iron-binding capacity (TIBC), transferrin, and ferritin. Dietary intake measures were assessed according to each subject's Recommended Dietary Allowance (RDA). The results were compared among three diagnostic groups, namely, benign, solid tumor, and hematopoietic. The nutrient lowest in intake was iron. The overall measures revealed significant differences between the benign and hematopoietic groups in all parameters except TIBC and transferrin. A correlation coefficient of 0.55 (p less than 10(-5) between transferrin and TIBC was generated in our patients. Significant differences were noted for ferritin in the acute lymphocytic leukemia (p = 0.0001) and lymphoma (p = 0.0007) groups when compared with the benign group. A correlation coefficient of 0.55 (p less than 10(-5) was generated in our patients. A 3-month follow-up assessment was conducted in order to document the effects of therapy. Tumor response and progression was compared to changes in ferritin levels from baseline to follow-up. Our results support the literature, that ferritin is a sensitive tumor marker in various malignancies.