Spontaneous non-traumatic urinary collecting system ruptures without distal obstructive causes are rare and uncommon. They should be considered in the differential diagnosis of renal colic or acute abdomen. Here, we present a case of spontaneous rupture of the left proximal ureter with perirenal fluid extravasation without an identified cause. The patient was treated conservatively and in the first week, symptom improvement was shown by control imaging methods. Ureteral stent placement or percutaneous nephrostomy, even open surgery are options for the management of spontaneous rupture of the urinary collecting system, however, conservative management may be an option for selected patients.