Steinert myotonic dystrophy is a multisystemic disease, autosomal dominant, with a wide spectrum of severity and clinical manifestations. The most severe form is one that manifests in the neonatal period, called congenital myotonic dystrophy. This condition is distinguished by overall hypotonia at birth and respiratory function compromise. Complications are frequent, mainly psychomotor development delay, growth failure, food difficulties and constipation. It is associated with a poor prognosis, with an overall mortality of up to 50% of severely affected children. We present five patients with congenital myotonic dystrophy in order to describe clinical manifestations, diagnosis, treatment and prognosis. Existing data in the literature on psychomotor development, complications and prognosis of survivors with congenital myotonic dystrophy are scarce. In our case studies, we have found significant chronic psychomotor limitations.