Objective：To explore the impact of the course of non -traumatic osteonecrosis of the femoral head（ONFH）on pain， functional recovery，and quality of life after total hip arthroplasty（THA）. Methods：A retrospective analysis was conducted on patients diagnosed with Association Research Circulation Osseous（ARCO）stage Ⅲ and Ⅳ ONFH who underwent THA at the First Affiliated Hospital of Nanjing Medical University between September 2022 and March 2024. Patients were divided into the short course group （course of disease ≤3 years）and long course group（course of disease>3 years）according to the length of the course of disease. Comparisons were made between the two groups regarding the surgery time，length of hospital stay，total blood loss，preoperative and postoperative visual analogue scale（VAS）pain scores，Harris hip joint function scores，leg length discrepancy（LLD），muscle fat infiltration（MFI），pelvic obliquity angle（POA），and the incidence of postoperative complications. Results：A total of 219 patients were included，within 149 patients in the short course group and 70 in the long course group. Compared to the short course group， patients in the long course group exhibited longer surgery time（P < 0.001）and hospital stays（P=0.036），greater total blood loss（P= 0.016），higher VAS pain scores on postoperative days 3，5，and 1 month（P=0.034，P < 0.001，P < 0.001），while lower Harris hip function scores at 1 month postoperative（P < 0.001）. Additionally，there was a greater preoperative LLD，MFI，and larger preoperative and postoperative POA in the long course group（P < 0.001）. However，there was no significant difference between the two groups in VAS pain score at 3 months，hip Harris scores at 3 and 6 months，leg length discrepancy，or postoperative complications（P > 0.05）. Conclusion：Compared with patients with a long disease course，patients with a short disease course have better short -term outcome after THA treatment.