The optimal type of reconstruction after intercalary tumor resection is unclear. Megaprosthetic and biologic reconstructions may restore bone stock, but their complexity may result in complications and delays in rehabilitation and initiation of adjuvant treatment. Instead, cement spacer permanent reconstruction can be performed as index surgery. The authors studied the files of 20 patients who had bone tumors of the humerus and femur and underwent wide margin resection and permanent cement spacer intercalary reconstruction. Mean follow-up was 52 months (range, 2-255 months). The authors evaluated the survival and function of the patients and the outcome of the cement spacer reconstructions. Five patients who had metastatic bone disease died of their disease with their cement spacer reconstruction in place without complications. One patient who had bone sarcoma experienced a local recurrence that was treated with hip disarticulation. Three patients who had bone sarcomas were converted to biologic reconstruction because of disease remission and had improved prognosis without complications related to cement spacer reconstruction. Two patients experienced mechanical failure of femoral reconstruction and underwent revision with an intercalary biologic reconstruction. No patient who had a cement spacer humeral reconstruction experienced a complication, and no patient experienced infection of the reconstruction. Mean Musculoskeletal Tumor Society score of the patients with cement spacer humeral and femoral reconstructions was 85% and 82%, respectively. [. 2021;44(4):e593-e599.].