Giant cell tumor of the small bones of the hands and feet is rare. Giant cell tumors in these locations develop at young age, are more commonly multifocal, and show the higher risk of recurrence than those at the end of the long bone. It should be differentiated from the other lesions of the hands, such as giant cell reparative granuloma, aneurysmal bone cyst and enchondroma. We experienced a case of giant cell tumor in the proximal phalanx of the left hand with swelling and pain. Curettage and bone graft were performed. Histologically large number of giant cells were distributed diffusely in the highly cellular stroma containing sheets of mononuclear cells. Secondary aneurysmal bone cyst and hemorrhage were associated.