In order to clarify the relationship between benign epilepsy of children with centro-temporal EEG foci (BECCT) and febrile convulsions (FC), we compared the previous and family histories of FC of one hundred children with BECCT, aged 3 years to 13 years, with those of 100 non-epileptic controls matched for age and sex. The incidences of FC in children with BECCT and non-epileptic controls were 18% and 8%, respectively (P less than 0.05). Forty-eight children (48%) with BECCT and 21 (21%) non-epileptic controls had positive family histories of FC within third-degree relatives (P less than 0.001). Of the fourteen pairs of siblings, one of each having BECCT and the other FC, we conducted an EEG examination in 7 siblings. All of these 7 siblings exhibited rolandic discharges (RD) on EEG. These observations strongly suggested a genetic link between BECCT and FC.