Our study suggests that the hemi-ESES/CSWSS syndrome has electroclinical features compatible with an epileptic encephalopathy. The most commonly used treatments were clobazam, ethosuximide, and sulthiame, alone or in combination. In refractory cases, high-dose corticosteroids were administered. Although the number of patients in this study is too low to draw definite conclusions, we consider that in children with hemi-ESES/CSWSS secondary to a unilateral lesion, surgery should be considered.