Metachromatic leukodystrophy (MDL) is a hereditary lysosomal inheritance disorder with autosomal recessive transmission. It is due to the deficiency of the enzyme arylsulphatase A or it’s activating protein soposin B. It can occur at any age, but the infant form is the most frequent. The diagnosis is based mainly on data from brain magnetic resonance imaging and the arylsulfatase a dosage. We report a serie of 04 cases collected in the pediatric department at Rabat's children's hospital, allowing us to know the clinical and paraclinical characteristics of the disease, as well as the current situation in the field of therapeutic