A blunt renal trauma (RT) diagnosis can present challenges. It demands increased clinical suspicion, taking into consideration patient history, mechanism of injury, and clinical and laboratory findings. Final diagnosis may be confirmed radiographically or intraoperatively. A thin, 22-year-old female with severe right flank pain appeared ambulatory in the emergency department. The pain appeared 1 h previously, following a common incident in a city bus, where the patient was as a standing passenger. The bus was moving in an urban area at low speed and decelerated rapidly. Another standing passenger fell on the patient, causing her right flank area to be compressed onto the bus banister for a few seconds. Clinical findings were insignificant. Laboratory examinations revealed only a nonvisible hematuria. Chest X-ray and abdominal ultrasonography were normal. Due to pain severity, an abdominal computed tomography scan was performed and revealed a grade-4, parenchymal RT with extravasation of contrast medium in delayed images. The patient underwent double-J stent insertion and had an uneventful recovery. She presented no complications at 5 mo postinjury. Major RT can be a result of an insignificant, blunt injury in a thin patient; thus, taking into consideration body habitus is of paramount importance in diagnostic evaluation.