The case of a 1-year-8-month-old-boy with cerebral infarction after varicella infection is reported here. Brain magnetic resonance (MR) angiography revealed segmental narrowing of the left middle cerebral artery which became normal 8 months later. The MR angiography well demonstrated the time course of the vascular involvement in the present patient. In cerebral infarction after varicella infection, the proximal portion of the main cerebral arteries were frequently damaged therefore MR angiography is useful for diagnosis and therapeutic decision-making. Moreover, serial MR angiographic studies can clarify the natural course of vascular changes in varicella virus-related cerebral infarction.