Background <p>The horseshoe kidney (HSK) is the most common upper urinary system congenital defect. In adults, it is usually asymptomatic and is mostly detected during radiological diagnostics such as ultrasound, intravenous pyelography, and computed tomography. It is distinguished by the merging of the kidney at either the upper or more frequently the lower pole, resulting in an isthmus that connects the two sides and forms a recognizable U-shaped arrangement. Renal trauma is present in nearly 1–5% of all injuries, with the kidney being the most frequently affected urinary system organ, while blunt force injury accounts for 19% of kidney injuries in people with preexisting renal diseases.</p> Case presentation <p>A 73-year-old cyclist involved in a rear-end collision sustained multiple traumatic injuries, including a horseshoe kidney exhibiting irregular tissue structure, hematomas, and vascular leakage. Computed tomography scan indicated the presence of intracerebral and subarachnoid hemorrhages, pleural effusions, as well as injuries to the thoracic vertebrae and spleen. Renal arteriography revealed contrast extravasation in the isthmus, which was addressed through superselective coil embolization, resulting in favorable post-procedure outcomes. Despite stable renal function, clinical deterioration occurred, necessitating thoracic drainage for pleural effusions. Subsequent imaging ruled out additional vascular leakage; however, the patient ultimately died from pulmonary thromboembolism. This case highlights the intricacies of managing polytrauma with uncommon renal anomalies and related complications.</p> Conclusions <p>The selection of appropriate treatment strategies for uncommon emergencies like this presents substantial challenges. This case report emphasizes the complexity of managing rare renal trauma and contributes to the development of a potential standardized approach for such emergencies.</p>