We describe a case of acute rupture of the left proximal ureter as a result of lithiasis. The patient presented with a clinical picture of renal infarction: unilateral flank pain, more than 500 red blood cells per microliter urine and increased serum LDH levels. Abdominal ultrasound as well as a CT scan showed no abnormalities. Only CT angiography of the kidneys was able to demonstrate an acute rupture of the left proximal ureter with extravasation of contrast. Intravenous pyelogram confirmed this rupture with leaking of the contrast. One day after admission the patient urinated a 2 mm large calciumoxalate-monohydrate stone, the likely cause of the rupture. The rupture healed spontaneously. A review of the literature is given.