Primary merosin (laminin α2 chain)-deficient congenital muscular dystrophy (CMD) is a uncommon and severe form of CMD, which is caused by the mutations in the laminin α2 chain gene. It is an autosomal recessively inherited form of muscular dystrophy that is associated with severe neonatal hypotonia, a high serum creatine kinase level, and abnormal brain imaging without intellectual dysfunction. We report a case of merosin-deficient CMD confirmed by the immunocytochemical analysis of the frozen muscle biopsy. This is the first case of merosin-deficient CMD in Korea.