It is known that rotavirus gastroenteritis can accompany some neurological manifestations, including encephalitis/encephalopathy or seizures. However, the detailed pathogenesis involved has not been fully understood. To date, acute cerebellitis associated rotavirus gastroenteritis has not been previously reported, except for one case. Herein, we describe two cases of acute encephalitis/encephalopathy and concurrent cerebellitis, associated rotavirus gastroenteritis. Following vomiting and diarrhea, case 1 experienced convulsions and consciousness disturbance and case 2, transient loss of consciousness with eye deviation. After these symptoms subsided, cerebellar signs became evident and a brain MRI showed cerebellar involvement in both cases. Both cases showed speech disturbances, such as mutism, slow speech and dysarthria. In this report, we will discuss the possible pathogenesis of rotavirus associated acute encephalitis/encephalopathy and concurrent cerebellitis.