Background: Muscular dystrophies are a type of myopathies, mostly of genetic etiology, characterized by progressive muscle weakness. Within muscular dystrophies, Muscular Dystrophy of Duchenne / Becker (DMD / B) is the most frequent. It is produced by genetic variations in the DMD gene, leading to the absence or deficiency of the dystrophin protein.Topic: Dystrophin is a protein that is part of a complex. In the absence of the protein, some are generated that lead to the degeneration of the muscle fiber. It has a variable clinical spectrum, being the less severe and later onset form considered as Becker Muscular Dystrophy in comparison to the Duchenne Muscular Dystrophy of early onset and of greater severity, however, in some cases its classification is not so easy in this way. DMD / B does not have a curative treatment and currently treatments are focused on symptomatic relief and management of complications. New therapies have recently been developed that aim primarily at correcting the molecular defect in the DMD / B gene by inducing the expression of a functional or semi-functional protein.Conclusions: DMD / B is the most frequent and severe type of muscular dystrophy, which generates great disability and with a short life prognosis. Early diagnosis is essential for the establishment of management, which must be multidisciplinary, with the aim of delaying the onset of loss of muscle function and loss of ambulation.