BACKGROUND: The purpose of this study was to describe and analyse the most severe casualties from the flash flood and mudslides occurring on 14 July 2021 in Germany, focusing on patients who were treated in the closest and largest level I trauma centre in the region the disaster occurred. METHODS: A single-centre retrospective study design was employed, and all patients treated because of the flooding and mudslides who needed inpatient treatment were documented. Data on each patient's demographic characteristics, type of injury, number of surgeries, duration of hospitalisation, operation time, revision rate, injury severity score (ISS), and complications were collected. The primary outcome measure was status at discharge. RESULTS: Within the first week after the flood, a total of 63 patients were documented. Forty-one patients were treated on an outpatient basis in the emergency unit, and 22 patients were hospitalised. Of those hospitalised, 15 patients needed surgical treatment in the operation theatre. The most common injuries were fractures of the lower extremity (n = 7) and soft tissue wounds (n = 4). Overall, 20 surgeries were performed; the mean hospital stay was 7.2 ± 6.4 days, and the mean ISS was 5.7 ± 2.7. CONCLUSION: The July 2021 flood disaster was one of the largest in German history. The included patients showed complex injuries of various types. Because of the effects of climate change, orthopaedic surgeons might face higher numbers of casualties affected by natural disasters. Learning more about the management and profile of these injuries can become a future challenge for orthopaedic and trauma surgeons.