Abstract:[Objective] To investigate the clinical efficacy of 3D printing-assisted open reduction and internal fixation (ORIF) of Sand- ers type III calcaneal fractures. [Methods] A retrospective study was performed on 80 patients who underwent ORIF for Sanders type III cal- caneal fractures in our hospital from June 2017 to September 2019. According to preoperative doctor-patient communication, 43 patients were treated with 3D printing assisted ORIF, while the remaining 37 patients were with conventional ORIF. The perioperative, follow-up and imaging data were compared between the two groups. [Results] All the patients in both groups had operation completed successfully without serious complications. The 3D group proved significantly superior to the conventional group in terms of operation time, total incision length, intraoperative blood loss, intraoperative fluoroscopy times, postoperative ambulation, incision healing grade and hospital stay (P<0.05) . All patients were followed up for (16.2±4.9) months on an average, and the 3D group resumed full weight-bearing activity significantly earlier than the conventional group (P<0.05) . The VAS scores decreased significantly (P<0.05) , while the AOFAS score, Maryland score and foot varus- valgus range of motion (ROM ) increased significantly in both groups over time postoperatively (P<0.05) , which in the 3D group proved significantly superior to the conventional group at all corresponding time point after surgery (P<0.05) . With regard to imaging, the calcaneal width, calcaneal height, Gissane angle and Bohler angle significantly improved in both groups after operation compared with those before operation (P<0.05) , whereas which were of no significant difference between the two groups at any corresponding time points (P> 0.05) . [Conclusion] 3D printing-assisted open reduction and internal fixation of Sanders type III calcaneal fractures does shorten the opera- tion time, reduce the amount of blood loss, promote functional recovery and reduce complications.