摘要Objective Total knee arthroplasty is one of the most common orthopedic surgeries. Readmission due to severe complications after total knee arthroplasty is a grave concern to surgeons. In this study, we evaluated the risk factors for severe complications after primary total knee arthroplasty. Methods We retrospectively collected clinical data of 2,974 patients who underwent primary total knee arthroplasty from July 2013 to June 2019 in our hospital. Postoperative complication ≥ grade Ⅲ was defined as severe complication according to Clavien-Dindo classification system. Binary logistic regression was used to identify the predictive risk factors for severe complications. Results The complication rate after primary total knee arthroplasty was 6.8％ and severe complication rate was 2.5％. Male (OR = 2.178, 95％CI: 1.324-3.585, P = 0.002), individuals above 75 years old (OR = 1.936, 95％CI: 1.155-3.244, P = 0.012), arrhythmia (OR = 2.913, 95％CI: 1.350-6.285, P = 0.006) and cerebrovascular disease (OR = 2.804, 95％CI: 1.432-5.489, P = 0.003) were predictive risk factors for severe complications after primary total knee arthroplasty. Conclusion Advanced age, male, arrhythmia, and cerebrovascular disease might be patients-related risk factors for postoperative severe complications after primary total knee arthroplasty. Special attention should be paid to patients with risk factors.