Giant cell tumor is usually found around the knee joint, especially in the distal femur or proximal tibia. Despite being classified as benign, it has unusual biological behavior of local aggressiveness and tend to have severely destructive lesion and develop rare pulmonary metastasis. Therefore, when the patient is presented to the physician with an expansile lytic lesion of challenging clinicopathologic entity extending to subchondral bone, the physician faces up to difficulties in treatment. We report a case of 25 years old patient having recurrent giant cell tumor in the right distal femur which developed metastasis to lung. The primary bone lesion was treated with local curettage and fillings with methylmethacrylate, but when he returned to the hospital two years later, the recurrence had developed with lung metastasis.