Little documentation of the correlation between MR imaging findings in isolated cerebellar cortical dysplasia (CCD) and its neuropathologic characteristics exists in the recent literature. We documented a postmortem neuropathologic study of a clinically and radiologically well-documented case of CCD in a neonate with severe hypotonia and status epilepticus. MR imaging revealed a global vermian hypoplasia with marked cortical dysplasia. CCD was associated with a voluminous heterotopic mass. The postmortem neuropathologic study confirmed vermian hypoplasia and CCD, which consisted of right cerebellar cortical polymicrogyria with subcortical heterotopia. CCD is a pathologic entity that could be well diagnosed with MR imaging even in the neonatal period.