From September 1994 to April 1995, we encountered eight children, two boys and six girls, (aged 1 year 6 months to 9 years), presented with acute diarrhea followed by afebrile, generalized tonic-clonic seizures, or transient loss of consciousness with urine incontinence. Their biochemical data, including serum electrolyte levels, were within normal limits. The infective agent causing diarrhea was later proved by stool examination to be rotavirus, judged to be serotype G1 by reverse transcription - polymerase chain reaction (RT-PCR) typing. Cerebrospinal fluid (CSF) examinations performed in seven of the eight patients were within normal limits, and cultures for bacteria and virus were negative. The electroencephalograms (EEGs) performed from 1 to 13 days after seizure showed abnormal in six, and normal in two, patients. Follow-up EEGs, performed from 4 to 11 months after onset of seizure, were all normal. None had seizure recurrence despite the fact that no long-term anticonvulsant had been given. From observation here, the authors emphasize that there is a close relationship between rotavirus and afebrile seizure, and the course of afebrile seizure following rotavirus gastroenteritis is usually benign. Further studies are needed to elucidate the underlying pathogenesis.