Among patients with moyamoya disease, familial occurrence is observed in about 20%, suggesting the involvement of genetic factors. In this report, we describe the first predictive case of moyamoya disease in a boy born to a woman who underwent surgical revascularization for moyamoya disease when she was 3 years old. We educated the mother and her family not to miss his initial signs of the disease. His family could easily notice his brief episode of ischemic attack when he was 6 years old. He underwent superficial temporal artery–to–middle cerebral artery anastomosis and indirect bypass on both sides. The postoperative course was uneventful. In conclusion, it is quite important to educate the family not to miss the initial signs of disease in their offspring, at least when they have a genetic background of the disease, because early diagnosis and effective treatment are essential to improve the long-term outcome in pediatric patients.