This paper describes the prevalence of Duchenne, Becker Type II, limb‐girdle, facioscapulo‐humeral dystrophies and dystrophia myotonia in Alberta, Canada, as of January 1, 1979. Rates established for Duchenne, limb‐girdle, and facio‐scapulo‐humeral dystrophies in 1962 had all been lower. The incidence of each M.D. type is described during 1950–74 by either 5‐ or 10‐year periods and shows consistent declines. Increased prevalence, despite declining incidence, for each of the muscular dystrophies may indicate improved medical care and greater longevity for affe