Abstract Purpose To compare percutaneous anterior to posterior (AP) with posterior to anterior (PA) lag screw fixation for Haraguchi I posterior malleolar fractures by assessing radiographic and clinical outcomes. Methods Between January 2013 and June 2017, 49 patients with posterior malleolar fractures were treated with either anterior to posterior (group A,24 patients) or posterior to anterior(group B,25 patients) lag screws. Demographic data, length of follow-up, and postoperative AOFAS scores were the main outcome measurements. Immediate,6 months,12 months postoperative and final follow-up radiographs for residual gap/step-off were evaluated. Results All patients achieved bony uion. The PA group demonstrated superior radiological outcomes compared with the AP screw group in step-off and position problems of screws. There were no significant differences in the AOFAS scores and ROM during the follow up period. Conclusions AP and PA lag screw are both efficient methods for treating posterior malleolar fractures.PA lag screw leads to superior radiological outcomes which may result in better clinical outcomes in long term follow up.