Renal infarction usually occurs in patients with severe atherosclerosis or heart disease. We report a 68-year-old lady who presented with total occlusion of the left renal artery of acute onset. Detailed work up did not reveal any specific cause and the infarction was considered to be idiopathic. The patient presented two-and-half years later with atrial fibrillation, which was managed with anti-arrhythmic drugs. Retrospectively, we believe that the cause of renal infarction was embolization secondary to paroxysmal atrial fibrillation. She is doing well on anti-coagulants and anti-arrhythmic drugs and was maintaining sinus rhythm when last seen.