Isolated rupture of the renal pelvis secondary to blunt trauma is rare, though there is increased incidence in the setting of a pre-existing renal abnormality that predisposes the kidney to injury. We report a case of post-traumatic hemorrhage into the renal collecting system leading to delayed rupture of the renal pelvis in the setting of suspected chronic ureteropelvic junction obstruction. This case illustrates the difficulty in diagnosis of acute hemorrhage into the renal collecting system. Special attention should be given to a kidney with a pre-existing abnormality in the setting of trauma to prevent complications. A literature review of hemorrhage into the collecting system along with appropriate imaging and management are discussed.