Background: The aim of this study was to report the incidence of associated osteochondral lesions (OCLs) on postop CTs, which may benefit from arthroscopic treatment, in patients with rotational type ankle fractures with syndesmotic injury. The diagnosis and treatment of associated OCLs may be an additional benefit of the use of arthroscopy in the management of rotational type ankle fractures with syndesmotic injury. Methods: We retrospectively reviewed data of a prospective cohort study of patients who underwent open reduction and surgical fixation of an ankle fracture with syndesmotic injury. These patients underwent routine bilateral postoperative CT assessment. Two independent observers classified ankle fractures according to Weber and OCLs according to the classification system by Berndt and Harty. Fifty-nine patients were included. There were 19 (32%) Weber B type ankle fractures and 39 (66%) Weber C type fractures. One patient (2%) had fixation for a medial malleolus fracture and syndesmotic rupture without fibula fracture. Results: Talar OCLs were present in 8 patients (14%). In one patient, 2 OCLs were found, which resulted in a total of 9 lesions. Two lesions were found on the medial side, both anterior. The other 7 were located laterally, of which 1 was anterior, 3 central, and 3 posterior on the talus. According to the Berndt and Harty classification, 1 was classified as stage I, 4 as stage III, and 4 as stage IV. Conclusion: The prevalence of OCLs in ankle fractures with syndesmotic instability was 14%. We believe that lesions were arthroscopically accessible in 6 patients (10%). Moreover, most lesions were located on the lateral dome, and thus also potentially approachable through an anterolateral arthrotomy during open reduction and internal fixation. The majority of OCLs found in this series were Berndt and Harty type III or IV, and so likely would preferably have been addressed during the index procedure. Level of Evidence: Level III, diagnostic cohort study.