Management of large giant cell tumors of the proximal humerus is controversial because wide resection with reconstruction results in a poor functional outcome for most patients. We retrospectively reviewed the cases of six patients with Campanacci Grade III giant cell tumors of the proximal humerus to determine the feasibility of avoiding en bloc resections for large giant cell tumors in this location. We evacuated the tumor through curettage and then used burring (unless the remaining cavity was thinned and at risk for fracture) and phenolization, followed by packing of the defect with allograft cancellous bone. The mean age of the patients at surgery was 30 years, and the minimum followup was 2.5 years (mean, 5.6 years; range, 2.5-9.7 years). One of the six patients had local recurrence 1.2 years postoperatively and was treated with repeat intralesional surgery with no additional recurrence 5 years later. No other patient required additional treatment, had pulmonary metastases develop, or had progression to osteoarthritis. The mean Musculoskeletal Tumor Society and Toronto Extremity Salvage Score functional scores at last followup were 26 of 30 (range, 21-30) and 95% (range, 90%-100%), respectively. These functional scores are higher than reported scores for patients with segmental resection and reconstruction of the proximal humerus. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.