Abstract:[Objective] To compare the clinical outcomes of four versus three cannulated screws for internal fixation of Pauwels type III femoral neck fractures. [Methods] From January 2014 to November 2018, 70 patients with Pauwels type III femoral neck fracture were en- rolled in this study and randomly divided into two groups by lottery. Among them, 35 patients had fractures fixed with 4 cannulated screws (the four-screw group) , while the remaining 35 patients were treated with 3 cannulated screws (the three-screw group). Perioperative condi- tions, follow-up consequences and imaging data were compared between the two groups. [Results] All the patients in both groups had inter- nal fixations performed successfully with no vascular and nerve injury. The four-screw group consumed significantly longer operative time, associated with significantly more intraoperative bleeding, total incision length and intraoperative fluoroscopy frequency than the threescrew group (P<0.05) . However, there were no significant differences in hospital stay and the time to resume walking between the two groups (P>0.05) . The follow-up period lasted for 18 to 48 months with a mean of (26.41±5.02) months. To the latest follow-up, total hip ar- throplasty due to femoral head necrosis or nonunion was performed 5/35 (14.26%) in the four-screw group, whereas 7/35 (20.00%) in the three- screw group. The hip range of motion (ROM) in all directions and the Harris score was significantly increased over time in both groups (P<0.05) . At all the corresponding time points, the four-screw group proved significantly superior to the three-screw group in terms of ROMs and Harris scores (P<0.05) . With respect to radiographic evaluation, there was no significant difference in fracture reduction qual- ity in term of Garden's alignment index between the two groups (P>0.05) . However, the four-screw group was significantly superior to the three- screw group in terms of femoral head and neck shortening and neck- shaft angle (P<0.05) . [Conclusion] The four cannulated screws used in internal fixation of Pauwels type III femoral neck fracture does achieve better clinical outcomes than the three canulated screws.