**Abstract**

Moyamoya disease (MMD) is an occlusive cerebrovascular disease characterized by progressive stenosis or occlusion in the terminal portion of the bilateral internal carotid arteries, and affect both children and adults. In this pathology, which presents itself through ischemia or cerebral hemorrhage, an unusual compensatory vascular network (moyamoya vessels) develops at the brain's base in the form of collateral channels. MMD can present clinically as hemiparesis, dysarthria, aphasia, headache, seizures, visual deficits, syncope, or personality changes. Neuropsychologically, and even in the absence of obvious stroke, patients often present impaired attention, memory, behavior, and executive functions. This book chapter reviews the current literature regarding the neuropsychological deficits of MMD both in children and adults.

**Keywords:** Moyamoya disease, neuropsychology, cognitive outcome, pediatric moyamoya
