We treated 3 cases of fracture and 1 case of avascular necrosis of femoral head using autologous cultured osteoblasts injection. The stromal cells from the bone marrow were cultured to differentiate to osteoblasts for 4 weeks. The fracture sites of each patients were right ulnar shaft, left radial shaft, and left 5th metatarsal base. All of the fractures showed callus formations after 1 week of osteoblasts injection to the fracture site. After 4 weeks, callus formations were progressed. Avascular necrosis of femoral head was bilateral and both were Ficat stage II. Core decompression and allograft impaction were performed to the left, and core decompression and autologous cultured osteoblasts injection percutaneously after 4 weeks of the decompression operation were done to the right femoral head. CT images of 1 year from the operations showed trabecular bone formation and well maintained femoral head contour of the right femur, but resorption of the grafted bone for the left.