We describe a Turkish boy newly diagnosed with Fanconi anemia with mutation in the FANCA gene. The patient, with normal clinical phenotype and negative chromosomal breakage test result, presented with macrocytosis. No clinical or laboratory changes were observed in a follow-up period of 4 years. The diagnosis was confirmed molecularly after a prolonged and exhaustive investigation. He was found to be a compound heterozygote for 2 mutations in the FANCA gene (1 of which is novel, c. 4261-2A > C). We present this experience to alert physicians that Fanconi anemia should be considered in the differential diagnosis of otherwise unexplained macrocytosis during childhood.