Effective repair of damaged tissues and organs requires the coordinated action of several cell types, including infiltrating inflammatory cells and resident cells. Recent findings have uncovered a central role for macrophages in the repair of skeletal muscle after acute damage. If damage persists, as in skeletal muscle pathologies, macrophage infiltration perpetuates and leads to progressive fibrosis, thus exacerbating disease severity. I will discuss how dynamic changes in macrophage populations and activation states in the damaged muscle tissue contribute to its efficient regeneration. Conversely, dysregulation of the inflammatory response may lead to aberrant muscle repair and fibrosis development, as in muscular dystrophy progression.