: Steinmann pins are commonly used in orthopedics, with a low rate of complications. However, thermal osteonecrosis may occur when a pin is inserted using a drill. There have been no reports on late-onset fractures at the Steinmann pin insertion site. : A 32-year-old man who underwent surgery for a femoral shaft fracture 5 years ago complained of proximal thigh pain 1 month after the removal of the internal device. On physical examination, the patient showed a limping gait due to pain, and tenderness was observed on the lateral aspect of the proximal thigh. Magnetic resonance imaging was performed because the symptoms did not improve, despite conservative treatment. A new fracture line was observed in the lateral cortical bone of the proximal femur. It was found that a fracture occurred at the site where the Steinmann pin was inserted for a closed reduction at the time of the first operation. The patient was instructed to limit weight bearing and to use crutches while walking. Parathyroid hormone was additionally administered to promote bone formation. : Six months after diagnosis, a complete union was achieved at the subtrochanteric fracture site, and the patient’s pain subsided. : A fracture that occurs as a late onset at the provisional Steinmann pin insertion site is an extremely rare complication; however, orthopedic surgeons must consider this possibility and make more efforts to lower the occurrence of thermal damage. In addition, if the patient complains of pain in the region where the pin was inserted after surgery, surgeons should spare no effort to determine whether a new fracture has occurred.