We report a patient with congenital muscular dystrophy (CMD), developmental brain defects, and peripheral neuropathy. Marked hypotonia and plagiocephaly were noted at birth. Failure to thrive, generalized muscle weakness and wasting, absent deep tendon reflexes, partial seizures, and secondary microcephaly developed. Brain MRI showed a large area of cortical dysplasia, a thin but complete corpus callosum, and diffuse ventriculomegaly. Nerve conduction velocities were slow and creatine kinase levels only mildly elevated. Muscle biopsy showed dystrophic features with normal merosin, sarcoglycan, and dystrophin immunostaining. The Japanese Fukuyama CMD founder mutation was not detected. This is the first report of a patient with merosin-positive CMD, cobblestone lissencephaly, and demyelinating peripheral neuropathy.