Several dozen congenital myopathies are defined by clinical and morphological criteria. The application of the current generation of scientific techniques including immunohistochemistry and molecular genetics has resulted in the expansion of our knowledge and understanding of the well-established conditions including central core myopathy and centronuclear/myotubular myopathy and allowed greater understanding of the interrelationships of some of the less common or less well-established conditions. In the near future molecular genetics may allow the identification of the specific gene defect in many of these diseases. This article reviews the major congenital myopathies and presents some of the information gained by application of new technology to these conditions.