Introduction: The purpose of this study was first, to assess the relationship between preoperative INR (international normalised ratio) and postoperative complication rates in patients with a hip fracture, and second, to establish a threshold for INR below which the risk of complications is comparable to those in patients with a normal INR. Methods: We retrospectively reviewed the American College of Surgeons National Surgical Quality Improvement Program and found 35,910 cases who had undergone surgery for a hip fracture between 2012 and 2018. Cases were stratified into 4 groups based on their preoperative INR levels: Results: Of the 35,910 cases, 33,484 (93.2%) had a preoperative INR Conclusions: We found that an INR of