Massive splenic infarction (SI) is an extremely rare disease in childhood, the genesis of which is not always clear. Most often in children, SI develops against the background of oncohematological (in particular, myeloid leukemia), hematological (sickle cell anemia) and infectious (malaria, mononucleosis, cytomegalovirus infection) diseases and is small in size. Two own observations are presented, unique in the absence of a clear cause of SI and the massiveness of the lesion. In the first case, a 10yearold girl was admitted to the hospital on about the 10th day of illness with complaints of undefined abdominal pain, about which she had already twice applied to other hospitals in Moscow. SI was suspected on ultrasound and confirmed on CT, and then the echographic dynamics of SI was followed for more than 2 months. Against the background of anticoagulant, antibacterial and symptomatic therapy, recovery was achieved. In the second case, total SI was observed in a premature infant with severe multiple organ failure. The publication is extensively illustrated and contains a brief review of the literature.