Locomotion mediated by skeletal muscle provides a basis for the behavioral repertoire of most animals. Embryological and genetic studies of mouse, bird, fish and frog embryos are providing insights into the functions of the myogenic regulatory factors (MRFs) and the signaling molecules that regulate activity of MRFs. Nevertheless, our understanding of muscle development remains somewhat limited. Fundamental goals are to elucidate how mesodermal cells are induced during gastrulation to form muscle precursor cells and how muscle precursor cells acquire specific cell fates, such as slow and fast muscle cells. In this review, we focus on studies of zebrafish muscle development that have advanced our understanding of the molecular genetics of muscle cell induction and specification.