Objective：The use of drains in total knee arthroplasty（TKA）remains controversial. This study aimed to investigate the effects of intra-articular drainage on blood loss and joint function recovery in TKA. Methods：A retrospective analysis was conducted on patients with end-stage knee osteoarthritis who underwent TKA at the First Affiliated Hospital of Nanjing Medical University from September 2021 to October 2022. Patients were divided into a drainage group and a non-drainage group according to whether drains were placed intraoperatively. Postoperative blood loss，knee joint functional recovery index，postoperative complications，and follow-up results were compared between the two groups. Results：A total of 147 patients were included，with 53 cases in the non-drainage group and 94 cases in the drainage group. Compared to the non-drainage group，the drainage group had significantly less hidden blood loss （HBL）[（906.94±438.41）mL vs.（ 1 262.85±563.46）mL，P ＜ 0.001]，but there was no significant difference in transfusion rate or total blood loss（P ＞ 0.05）. The degree of lower limb swelling in the non-drainage group was higher than that in the drainage group at postoperative day 1，3，and 5，with significant differences noted at postoperative day 3[（9.31±4.47）% vs.（ 7.74±3.75）%，P=0.025]. The drainage group showed a significant increase in postoperative range of motion（ROM）of the knee joint compared to the nondrainage group（P ＜ 0.001），along with a significant increase in postoperative pain at day 3（P=0.029）and a decrease in postoperative ecchymosis rate（52.13% vs. 79.25% ，P=0.001）. However，there was no statistically significant difference in the incidence of postoperative deep venous thrombosis（DVT）between the two groups（P=0.552）. Both groups achieved primary healing of the incision without signs of infection such as redness，discharge，or liquefaction of fat. No cases of drainage obstruction，continuous bleeding at the drainage site，or dislocation or rupture of the drainage tube were observed in the drainage group. There were no cases of infection during the follow-up period in either group，and there were no significant differences in knee joint function recovery and pain level at 1 and 3 months postoperatively（P ＞ 0.05）. Conclusion：Intra - articular drainage in TKA can reduce HBL and alleviate early postoperative pain and swelling.