Facioscapulohumeral muscular dystrophy (FSHD) is a genetic disorder involving slowly progressive muscle degeneration in which the muscles of the face, shoulder blades and upper arms are among the most severely affected. It is the third most common inherited muscular dystrophy, affecting 1 in 20,000. The search for the molecular basis of the disease is of interest to all genetic researchers, involving a deletion outside a coding region resulting in over-expression of adjacent genes. This volume summarizes the current understanding of the disorder, including clinical, molecular and therapeutic aspects.