Fibrous-type left ventricular (LV) diverticulum is usually discovered incidentally. Most fibrous diverticula are clinically silent; they may, however, cause several fatal complications, such as spontaneous rupture. Here, we report a case in which multiple cerebral thromboembolisms occurred while a patient with a fibrous LV diverticulum was awaiting surgery. An 81-year-old woman was diagnosed as having an LV diverticulum and was scheduled for open surgery. Following admission for correction, she complained of headache, and magnetic resonance imaging revealed multiple cerebral infarctions. We recommend surgical treatment for asymptomatic LV diverticula to prevent systemic thromboembolism.