A 13-year-old HIV-infected girl presented with a rapidly progressive akinetic-rigid syndrome. Cranial magnetic resonance imaging revealed bilateral centrum semiovale lesions extending into the basal ganglia. Detailed histopathological study of a biopsy specimen from the involved regions resulted in a diagnosis of progressive multifocal leukoencephalopathy (PML). This case illustrates that an akinetic-rigid syndrome may be a rare presentation of PML. HIV-related PML may have unusual radiological features. Brain biopsy may be necessary to confirm PML in cases associated with atypical clinical and radiological presentations.