Summary. Syndesmotic malreduction or failure to restore fibular length are the leading causes for early reoperation after ankle fracture surgery. Anatomic fracture reduction and congruent ankle mortise can be achieved in the majority of cases following revision surgery. Introduction. The goal of ankle fracture surgery is to restore anatomical congruity. However, anatomic reduction is not always achieved, and residual talar displacement and postoperative malreduction predispose a patient to post-traumatic arthritis and poor functional outcomes. The present study aimed to determine the most common surgical errors resulting in early reoperation following ankle fracture surgery. Patients & Methods. We performed a chart review to determine the most common types of malreductions that led to reoperation within the first week following ankle fracture surgery. From 2002 to 2011, we identified 5123 consecutive ankle fracture operations in 5071 patients. 79 patients (1.6%) were reoperated on due to malreduction (residual fracture displacement > 2mm) detected in postoperative radiographs. These patients were compared with an equal number of age- and sex-matched control patients. Surgical errors were classified according to the anatomical site of malreduction: fibula, medial malleolus, posterior malleolus, Chaput-Tillaux fragment, and syndesmosis. Problems related to syndesmotic reduction or fixation were further divided into four categories: malreduction of the fibula in the tibiofibular incisura due to malpositioning of a syndesmotic screw, persistent tibiofibular widening (TFCS > 6 mm), positioning of a syndesmotic screw posterior to the posterior margin of the tibia, and unnecessary use of a syndesmotic screw. Results. The mean patient age was 44 years (18 to 80), and 49% were women. There were no differences between the groups regarding diabetes, tobacco use, peripheral vascular disease, or alcohol abuse. The most common indication for reoperation was syndesmotic malreduction (47 of 79 patients; 59%). Other frequent indications for reoperation were fibular shortening and malreduction of the medial malleolus. We identified four main types of errors related to syndesmotic reduction or fixation, the most common being fibular malreduction in the tibiofibular incisura. The most commonly combined errors were malreductions of the fibula and syndesmosis, which occurred together in 16 of 79 patients (20%). Fracture-dislocation (p = 0.011), fracture type (p = 0.001), posterior malleolar fracture (p = 0.005), associated medial malleolar fracture (p = 0.001), duration of index surgery (p = 0.001), and associated medial malleolar fixation other than with two parallel screws (p = 0.045) were associated with reoperation. Correction of the malreduction was achieved in 84% of reoperated cases. Conclusion. Early reoperation after ankle fracture surgery was most commonly caused by errors related to syndesmotic reduction or failure to restore fibular length. In the majority of cases, postoperative malreduction was successfully corrected in the acute setting