A 25 year-old man complained of pain at the distal interphalangeal joint of the middle finger for 3 months. The radiographs revealed an unicondylar osteolytic lesion at the head of middle phalanx. Enchondroma was initially suspected and curettage was performed, and final diagnosis was chondroblastoma. The size of the lesion increased and multiple septation developed at 9 months follow up. Curettage and bone graft was performed. Radiologic improvement was observed at 1 year after operation. Chondroblastoma developing at the phalanx is first report in our country, and this report can serve as a reminder at the diagnosis of osteolytic lesion in hand.