We experienced a case of cryptogenic renal infarction in a previously healthy 60-year-old man. He had no systemic atherosclerotic changes. Holter monitoring revealed no atrial fibrillation. Transthoracic echocardiography showed no thrombus. Because the onset occurred while he was swinging a golf club (a similar maneuver to holding the breath), further examination was performed with a view to detecting paradoxical embolism through the foramen ovale. A positive bubble test with the Valsalva maneuver during transesophageal echocardiography led to the diagnosis of patent foramen ovale (PFO). This was a suspected case of paradoxical embolism through a PFO leading to renal infarction.