We present the case of a woman with known risk factors for embolism with multiple kidney infarctions. She was admitted with left renal colic, discrete hematuria and subfebrility. She was under acenocumarolum treatment but without efficient anticoagulation. Ultrasound performed at the emergency room revealed smaller right kidney (congenital hypoplasia) and moderately enlarged left kidney with hypoechoic areas in the parenchyma. Computer tomography scan with contrast agent revealed multiple avascular areas within the left kidney. Evolution was favorable after efficient anticoagulation. Contrast enhanced ultrasound performed two weeks later revealed only one residual avascular area. Differential diagnosis was made with acute pyelonephritis, cholesterol embolism and acute tubular necrosis in a diabetic patient.