Chickenpox is a common infection of childhood. Central nervous system complications, such as cerebellar ataxia and meningoencephalitis, are estimated to occur in less than 1% of cases of chickenpox. Although transverse myelitis and hemiplegia have also, although rarely, been reported, hemiplegia associated with chickenpox and elevated anticardiolipin antibody has not been reported in the literature. We report the case of a 2.5-year-old boy who developed a right hemiplegia 3 weeks after the onset of a primary varicella infection. The serum level of anti-cardiolipin antibody IgG was markedly elevated. Brain magnetic resonance imaging (MRI) revealed an infarction involving the left globus pallidus, caudate nucleus, and posterior leg of the internal capsule. Laboratory studies ruled out all known causes of stroke. Neurologic signs and symptoms slowly improved with supportive treatment. Varicella infection should be considered one of the possible causes of acute ischemic strokes in children. Usually, two or more risk factors are detected in children with ischemic strokes, and we suggest that all possible causes of strokes be investigated in children with ischemic strokes.