Objective To explore the effectiveness of Nice knot technique for wound closure in Gustilo type ⅢA and ⅢB open tibial fractures. Methods A retrospective study was performed on 22 patients with Gustilo type ⅢA and ⅢB open tibial fractures, who underwent wound closure using the Nice knot technique and were admitted between June 2021 and June 2022. There were 15 males and 7 females. The age ranged from 18 to 67 years, with an average of 41.9 years. The causes of injury included traffic accident in 11 cases, falling from height in 7 cases, and heavy object injuries in 4 cases. Fractures were located on the left side in 9 cases and on the right side in 13 cases. And 9 cases were type ⅢA fractures and 13 were type ⅢB fractures according to Gustilo classification. All patients had extensive soft tissue injuries, and no vascular or neurological damage was observed. The time from injury to debridement was 3-8 hours (mean, 6.5 hours). The sizes of wounds before operation and at 2 weeks after operation were measured and wound healing rate at 2 weeks after operation were calculated. The wound healing time and wound healing grading were recorded. The Vancouver Scar Scale (VSS) score was used to assess the wound scar after wound healed and the excellent and good rate was calculated. Results The wound area was 21.0-180.0 cm2 (mean, 57.82 cm2) before operation, and it was 1.2-27.0 cm2 (mean, 6.57 cm2) at 2 weeks after operation. The wound healing rate at 2 weeks after operation was 76%-98% (mean, 88.6%). After operation, 2 cases needed to adjust Nice knot due to skin cutting and 1 case occurred soft tissue infection on the wound. The other patient’s wounds healed. The average wound healing time was 27.8 days (range, 18-44 days). And the wound healing were grade A in 13 cases and grade B in 9 cases. VSS score was 2-9, with an average of 4.1; 10 cases were rated as excellent, 10 as good, and 2 as poor, with an excellent and good rate of 90.9%. All patients were followed up 9-24 months (mean, 14.6 months). During follow-up, no deep infection or osteomyelitis occurred. Two cases experienced fracture non-union, and were treated with compression fixation and bone grafting. The fractures of the other patients all healed, with a healing time of 85-190 days (mean, 148.2 days). ConclusionNice knot technique can be used in wound closure of Gustilo type ⅢA and ⅢB open tibial fractures effectively, which is easy to operate.