Background: Maple syrup urine disease (MSUD) is an uncommon genetic autosomal recessive neurometabolic disorder. This disorder is identified by the burnt sweet scent of the urine of affected infants. Aim: the current study aimed to evaluate the effect of an instructional program on mothers' knowledge and practices regarding care for their children with maple syrup urine disease. Design: A quasi-experimental study design (pre-posttest) was used to fulfill the aim of the study. Setting: The study was conducted at the Genetic Outpatient Clinic in Mustafa Hassan Pediatric Hospital, is affiliated to Fayoum University Hospitals, and Abo El Rish (El Monira) Hospital affiliated to Cairo University Hospitals.