Objective To investigate the efficacy of surgical treatment of transapical displaced transverse acetabular fractures and its influencing factors. Methods From May 1990 to July 2006, 37 cases of transapical displaced transverse acetabular fractures were treated surgically, 26 males and 11 females, aged 22-64 years, with an average age of 34 years. The patients were grouped according to the quality of reduction, degree of comminution of the acetabular apex fracture, hip stability, and femoral cartilage damage, and were evaluated according to the postoperative X-ray reduction criteria and radiological assessment criteria of Matta and the modified Merle d’Aubigne and Postel functional scores. Results All patients were followed up for 16-121 months, with a mean of 88.6 months. Postoperative anatomical repositioning was performed in 31 patients, poor repositioning in 4 patients, and poor repositioning in 2 patients. Postoperative radiographs showed hip instability in 2 patients. According to the modified Merle d’Aubigne and Postel functional scores, the clinical outcome was excellent in 16 cases (43.24%), good in 14 cases (37.84%), acceptable in 4 cases (10.81%), and poor in 3 cases (8.11%), with an excellent rate of 81.08%; the long-term follow-up MattaX-ray outcome was excellent in 14 cases (37.84%), good in 15 cases ( 40.54%), 4 cases (10.81%), 4 cases (10.81%), and 4 cases (10.81%), with an excellent rate of 78.38%. The clinical efficacy correlated with the radiographic efficacy. The excellent clinical rate was 90.32% and 33.33% in the anatomically repositioned and non-anatomically repositioned groups, 58.33% and 92.00% in the comminuted and non-comminuted fracture groups, 0 and 85.71% in the unstable and stable hip groups, and 42.86% and 90.00% in the cartilage damage and no cartilage damage groups of the femoral head, respectively. Conclusion Poor fracture repositioning, comminuted fracture of the acetabular apex, hip instability and cartilage damage to the femoral head can directly affect the surgical outcome of trans-apical displaced transverse acetabular fractures.