We present a 40-year-old woman who experienced intermittent gross hematuria and left flank pain. The diagnosis of nutcracker syndrome was missed initially. A readily available diagnostic tool, abdominal ultrasound, can be a great help in making this diagnosis. Anatomical compression was disclosed by gray-scale ultrasonography and collateral circulation with varices on color Doppler. The definite diagnosis was also confirmed by computed tomography and renal vein and inferior vena cava phlebography and venous pressure manometry. Nutcracker syndrome should be kept in mind for patients with unknown causes of unilateral hematuria and abdominal pain. Modern treatment and moreprecise non-invasive imaging studies have been developed for diagnosing nutcracker syndrome. The usefulness of a readily available tool, ultrasonography, should be recognized by general practitioners.