Muscle satellite cells have been shown to be a heterogeneous population of committed myogenic progenitors and noncommitted stem cells. This hierarchical composition of differentiating progenitors and self-renewable stem cells assures the extraordinary regenerative capacity of skeletal muscles. Recent studies have revealed a role for asymmetric division in satellite cell maintenance and offer novel insights into the regulation of satellite cell function by the niche. A thorough understanding of the molecular regulation and cell fate determination of satellite cells and other potential stem cells resident in muscle is essential for successful stem cell-based therapies to treat muscular diseases.