Centronuclear myopathies are clinically and genetically heterogenous diseases with common histological findings, namely, centrally located nuclei in muscle fibers with a predominance and hypotrophy of type 1 fibers. We describe two cases from one family with autosomal dominant centronuclear myopathy with unusual clinical features that had initially suggested distal myopathy. Clinically, the patients presented with muscle weakness and atrophy localized mainly to the posterior compartment of the distal lower extremities. Magnetic resonance imaging revealed predominant atrophy and fatty changes of bilateral gastrocnemius and soleus muscles. This report demonstrates the expanding clinical heterogeneity of autosomal dominant centronuclear myopathy.