Renal infarction is a common clinical problem and often misdiagnosed because the symptoms are subtle. We are presented our patient who applicant with left flank pain and diagnosed renal infarction. 49-year-old male patient has come with 2 days of severe left flank. Pathologic were; left costovertebral angle tenderness, creatinine: 1.3 mg/dL, C reactive protein: 11.4 mg/dL. On Computed Tomography Angiography renal arteries there was no contrast matter transmission to left arcuat artery distale and there were ischemic regions. With renal infarction diagnose, patient was hospitalized.