Desmoplastic fibroma or desmoid bone tumor is a rare tumor described for the first time by Jaffe in 1958. It accounts for 0.1 to 0.3% of all benign bone tumors. To date, about 150 cases involving the locomotor system have been reported. Histology is required for certain diagnosis of desmoplastic fibroma. The tumor is composed of sparse fibroblasts in a rich background of collagen fibers, a histological presentation exactly the same as soft tissue desmoid fibroma. We report two new cases of desmoplastic fibroma of the locomotor system. The observations illustrate the radiological diagnosis. MRI was used to search for local extension in bone or soft tissues. Biopsy is necessary to confirm the diagnosis. The histological presentation may be difficult to recognized and distinguish from low grade fibrosarcoma. After treatment, the rate of local recurrence is high in the event of partial resection. Surgery is the optimal treatment, with tumor resection as wide as possible depending on the localization.