Muscle MRI has become a very useful tool in the diagnosis and follow-up of patients with muscle dystrophies. Muscle MRI provides us about many aspects of the structure and function of skeletal muscles, such as the presence of oedema or fatty infiltration. In the last years many reports have described the particular muscles that are involved in these muscle disease. This knowledge can facilitate the diagnosis in many cases. In the present paper we review the main changes observed in muscle MRI of patients with muscle dystrophies