© 2019 Elsevier Ltd Background: In the last decade, the biomechanics of reverse shoulder arthroplasty (RSA) for proximal humeral fractures in the elderly have led to more functional outcomes and greater pain relief. However, its use has also introduced a significant rate of complications. The purpose of this study is to assess the complication rate of RSA in these cases as well as the relationship to ASA score and basic disease history. Methods: We evaluate patients who underwent RSA due to acute proximal humeral fractures at three hospitals from 2010 to 2016. We analyze previous disease and anticoagulant treatment, American Society of Anesthesiologists (ASA) Physical Status Classification, and the transfusion rate to correlate these factors with major and minor postoperative complications at 7, 90, and 365 days. Results: We include 103 patients (104 shoulders) over 65 years of age. Mean age is 77.31 years (62–91), 20 of which are male. The overall rate of complications is 25%, with 17.4% minor and 7.6% major complications. We observe a statistically significant relationship between a higher ASA score (3,4) and major complication at 90 days (p = 0.024) and a trend (p = 0.072) towards a higher ASA score with minor complication during the first week. Rheumatoid disease significantly increases major complications at 90 days (p = 0.037). The transfusion rate is 11.5%. Conclusions: The overall major complication rate of RSA for acute fractures is low in the elderly population. Although, the patient's history (e.g. previous rheumatoid pathology, neurological diseases, or anticoagulant treatment) as well as their ASA score should be considered before RSA surgery. The higher the ASA score and the presence of rheumatoid disease, leads to a higher rate of major complications during the first 90 days after surgery. Level of evidence: Level IV; Case series; Treatment study.