BACKGROUND.: Fanconiʼs anemia (FA) is a rare autosomal recessive genetic disorder characterized by congenital anomalies, progressive aplastic anemia, and a predisposition for malignancies. Solid tumors in the head and neck region, especially in the tongue, are rarely observed. Management of these patients is a challenge because of hematological complications and increased toxicities. METHODS.: We report a case of Fanconiʼs anemia in a 27-year-old man with carcinoma of the base of tongue (T2N0M0) who was treated with radical radiation therapy to a dose of 70 Gy/35 fractions/51 days. We have also done in vitro radiosensitivity tests. RESULTS.: The patient tolerated the radiation treatment well and completed it without any interruptions. In vitro studies did not show any increased radiosensitivity in this patient. CONCLUSION.: Head and neck cancer in a patient with FA requires individualized treatment. The decision about opting for different modalities should be based on a balanced approach with respect to locoregional control and toxicities of the treatment. © 2009 Wiley Periodicals, Inc. Head Neck, 2010