Acute cerebellitis (AC) is an inflammatory process involving the cerebellum. Usually, this pathology is bilateral; it is unusual to have a unilateral cerebellitis. Only seven cases of hemicerebellitis have been reported in the literature. Here, we review the literature and report the magnetic resonance imaging (MRI) and proton-magnetic resonance spectroscopic (+H-MRS) findings of a case of acute hemicerebellitis in a 15-year-old girl presenting with 15 days' history of headache.