BACKGROUND: Bone grafts have been used for augmentation and improving stability of reduced fractures in proximal humeral fractures. The aim of this study was to analyze the clinical and radiological outcomes after the use of cancellous bone allografts (CAs) for augmentation in 3- or 4-part proximal humeral fractures, and compare with fibular strut allografts (FAs). METHODS: Between November 2016 and February 2018, 55 patients, followed for at least 1 year, with 3- or 4-part proximal humeral fractures fixed with locking plates were included and grouped according to the type of allograft bone used for augmentation. In this retrospective analysis, we assessed and compared the clinical and radiological outcomes of the 2 groups, using the visual analog scale score, the Constant-Murley score (CMS), the disability of the arm, shoulder, and hand (DASH) score, the range of movement, neck-shaft angle (NSA), humeral head height (HHH), and the changes of NSA and HHH, as well as recording any complications. The repeatedly measured clinical and radiological outcomes were analyzed by linear mixed models. The differences in outcomes between groups at the final follow-up were compared using Student's t test. RESULTS: There were 28 patients in the CA group and 27 patients in the FA group with an average follow-up of 14.5 months. The mean age of all patients was 64 (36-86). Nonsignificant group effects were observed on CMS (ß = -8.792, P = .216), DASH (ß = 1.329, P = .094), NSA (ß = 1.432, P = .752), and HHH (ß = 1.660, P = .628). At the final follow-up, the patients in the CA group showed no significant differences in visual analog scale (1.8 vs. 2.2, P = .276), CMS (81.5 vs. 75.4, P = .072), and DASH (11.0 vs. 13.5, P = .235) scores compared with the FA group. There were no significant differences in the change of NSA (6 vs. 4, P = .387) or HHH (1 vs. 2, P = .261). CONCLUSIONS: Patients with 3- or 4-part proximal humeral fractures treated with locking plates combined with CAs have good clinical and radiographic outcomes, similar to those treated with FAs.