Holoprosencephaly is a rare CNS developmental defect with midline cleavage of embryonal forebrain during the fourth week of fetal development characterized with s single ventricle. Holoprosencephaly is divided into three types by the degree of the brain cleavage : alobar, semilobar, and lobar. Depending on the degree of defected regions, there exist variable clinical symptoms and signs such as stillbirth, hypotonia, apnea, convulsion, delayed development and visual disturbance. It was frequently associated with the deformity of the brain as well as the midline facial structures. Advances in neuroimaging over the past decades have led us to a better understanding of the pathogenesis and the variability of holoprosencephaly. As a result, a lot of cases of holoprosencephaly with various clinical and pathologic findings have been reported. We experienced a case of isolated interhemisphere fusion of frontal lobes with intact septum pellucidum in a child with febrile status epilepticus. Is it a variant of holoprosencephaly?