Twelve cases of acute arterial renal infarction with their clinical background and roentgenographic findings are reviewed. Five representative examples are presented in detail. Sudden onset of nonspecific abdominal pain is the predominant symptom. Microscopic hematuria and albuminuria are frequent urinary findings. A definitive diagnosis can be established only by roentgenographic means. The intravenous pyleogram is an important diagnostic study and shows nonfilling of calyceal structures, with distortion and stretching, or nonfunction of an entire kidney. A retrograde pyelogram demonstrates normal architecture of the collecting system. The renal angiogram will localize the lesion and delineate the extent of the infarct. In some cases emergency surgery will save the involved kidney.