Abstract:[Objective] To introduce the surgical technique and preliminary clinical outcomes of the lateral four-cut osteotomy for cor- rection of malunion of calcaneus fractures. [Methods] From January 2016 to October 2019, 19 patients received the lateral four-cut osteoto- my for correction of malunion secondary to calcaneus fractures. The patients were placed on the healthy side, and a transvers incision was made under the tip of lateral malleolus to expose the calcaneus. According to the preoperative plan, four-cut osteotomy on calcaneus was conducted, including the first cut on the lateral wall of calcaneus, the second cut on the periarticular bone, the third cut outside to sustentac- ulum tali and the fourth cut on posterior tuberosity vertically or in curvature. After that, the articular surface was restored with correction of deformity and bone autografting for bone defect. Finally, plate fixation was performed, whereas Achilles tendon lengthening was added if necessary. [Results] All the 19 patients had operation completed successfully without serious complications. The follow-up period was last- ed for 9~30 months. Compared with those preoperatively, the VAS and AFOAS scores, as well as the height, width, Bohler angle and the Gissane angle measured on radiographs significantly improved at the latest follow up (P＜0.05) . [Conclusion] This lateral four-cut osteoto- my does effectively restore the height, width, length, the Bohler and Gissane angles of the calcaneus to resume the biomechanical alignment of the foot for malunion of calcaneus fractures.