The article presents information about a rare case of Pompe disease. It is a glycogen storage disease. Pompe disease is a rare autosomal recessive disorder caused by deficiency of acid α-glucosidase (acid maltase deficiency). The defect of this enzyme leads to the accumulation of glycogen in the lysosomes of various tissues, with the development of the most pronounced changes in the skeletal muscles, myocardium and liver. During the third screening of a pregnant woman, the ultrasonography of the fetus’s heart revealed the myocardial hypertrophy of the left ventricle perceived as posthypoxic. After delivery, the newborn underwent the ultrasound examination and molecular genetic studies. Firstly, the hepatomegaly and cardiomegaly were diagnosed. Then an infantile form of Pompe disease was found. The patient got enzyme replacement therapy without positive result. The death occurred at the age of 2 years and 5 months as a result of cardiovascular disease failure. Macroscopically, the sizes of the internal organs were increased. The microscopic examination demonstrated glycogen deposition in the myocardium, skeletal muscles, mucous membranes of the organs of the gastrointestinal tract, liver, kidney, spleen and adrenal glands.