Many surgical procedures are available to treat the bone defect of benign bone tumors, including the use of calcium sulfate to fill the bone defect after curettage of the tumors. The purpose of our study was to review our experience in 19 patients with benign bone tumors treated with this procedure. The patients’ clinical functional outcomes and radiographic studies were reviewed over a mean follow-up of 37.6 months. Their histopathologic results showed 8 simple bone cysts, 3 enchondromas, 2 chondroblastomas, 2 giant cell tumors, 1 fibro-osseous lesion, 1 case of fibrous dysplasia, and 2 aneurysmal bone cysts. Their mean Enneking Function Evaluation System score was 29.8 in the upper extremities and 29.5 in the lower extremities. On postoperative radiography, their photodensity ratio was 92%. Only two patients (10.5%) had tumor recurrences, and no complications occurred. Surgical-grade calcium sulfate pellets are useful bone graft substitutes in the treatment of bone defects due to benign bone tumors.