Acute cerebellar ataxia (ACA) in childhood following viral infection is a self-limited disease. We present a boy with recurrent episodes of paraneoplastic cerebellar ataxia associated with a ganglioneuroma. A 20-month-old boy developed the first episode of cerebellar ataxia after nonspecific respiratory tract infections. During this episode he showed a wide gait and truncal ataxia with intention tremor and horizontal nystagmus. Our initial diagnosis was ACA, and gradual improvement of ataxia was observed thereafter. At 2 years and 6 months, similar cerebellar symptoms recurred after respiratory tract infections. Speech difficulty and cognitive problems developed thereafter. We suspected paraneoplastic syndrome. Computed tomography revealed a retroperitoneal tumor, and autoantibodies against GluR epsilon 2 were detected in the cerebrospinal fluid. After the tumor resection, the cerebellar symptoms did not recur and speech difficulty and cognitive problems improved gradually. Recent neuroimaging and neuropsychological studies have revealed that cerebellar function contributes to higher brain functions including cognition and learning. We will follow up this patient's long-term cognitive function and consider special educational support and programs.