We report a new case of infantile idiopathic hemiconvulsion-hemiplegia syndrome (HH). A prolonged right-sided febrile convulsion was followed 4 days later, by right hemiconvulsive status epilepticus, documented by video-electroencephalogram (EEG) recording. The child developed an ipsilateral hemiplegia, partially improved during the first month of follow-up. Sequential cerebral magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H-MRS) at 6, 15, 30 days of follow-up showed a cytotoxic edema in the left hemisphere and a subsequent necrosis. At 1-year of follow-up, we performed MRI control because of febrile convulsion lasting few minutes that confirmed a non-progressive left hemisphere atrophy. After 2 years, the patient was seizure-free, with a mild right hemiplegia and language skills deficit. We discuss the unclear pathogenesis of HH through sequential neuroradiological evaluation.