A 59-year old man presented with severe left flank and lower abdominal pain after vigorous golfing, exhibiting left costovertebral angle tenderness. He had managed hypertension and diabetes, with no history of recent trauma or endovascular procedures. Laboratory tests showed unremarkable complete blood cell counts, serum creatinine levels, and urinalysis results. Computed tomography (CT) revealed a left renal infarction and the presence of dual left renal arteries with narrowing and irregularity in the left upper renal artery with an intraluminal hematoma, suggesting renal artery dissection. Aneurysmal dilatation proximal to the dissection site was also noted (Figure 1A). Cardiac evaluations, including electrocardiogram, Holter monitoring, and echocardiography revealed no arrhythmias or intracardiac masses/thrombi. Coagulation tests were normal. We concluded that spontaneous renal artery dissection (SRAD) caused the acute renal infarction. Given his stable blood pressure and renal function, we decided to treat the patient with anticoagulation without endovascular intervention. Oral warfarin therapy was maintained for 6 months. A follow-up CT scan revealed segmental atrophy of the infarcted site of the left kidney, and the dissected left upper renal artery showed recovery of luminal flow, disappearance of the intraluminal thrombus, and regression of the aneurysm. (Figure 1B). CT angiography excluded other underlying arteriopathies such as fibromuscular dysplasia or connective tissue disorders (Figure 2). Warfarin was replaced with low-dose aspirin as no thromboembolic risk factors were identified. SRAD is a rare condition but may occur during golfing owing to intimal tearing, which can be caused by direct stretching or acceleration/deceleration forces. SRAD should be considered in patients presenting with acute flank or abdominal pain after strenuous exercise. The management of SRAD varies from medical to endovascular treatment and surgery. In the present case, the patient with stable blood pressure and renal function achieved a good clinical outcome with medical treatment alone.