['Carbamazepine is a commonly used anticonvulsant agent; however, it has been linked with various blood cell abnormalities. This study evaluated the effect of low-dose folic acid supplementation on the prevention of carbamazepine-induced hematological derangements in children.', 'This randomized clinical trial was conducted in children with epilepsy who received carbamazepine monotherapy. Group 1 received carbamazepine alone, and group 2 received carbamazepine plus folic acid. The two groups were age- and sex-matched. Each group comprised 41 children with epilepsy. Complete blood counts were obtained before starting medication (baseline) and then serially. The patients were followed for at least 1 year.', 'In group 1, 31.4% of the patients developed leukopenia and 17.1% neutropenia, but in group 2, these figures were 14.6 and 9.8% (P = 0.067 and P = 0.331, respectively). At the end of the first year of follow up, white blood cell and polymorphonuclear cell counts were significantly higher in group 2 (P = 0.007 and P = 0.001, respectively). Hemoglobin concentration dropped in group 1, but rose slightly in group 2; these changes were significant. Platelet, lymphocyte, and monocyte counts and changes in serial blood tests did not differ significantly between the two groups.'] Does folic acid supplementation reduce the development of some blood cell abnormalities in children receiving carbamazepine?