Primary splenic cysts (SC) are rare in children and are registered with a frequency of 0.07% to 1.0% of all surgical diseases of the abdominal cavity [2, 7, 13]. Beginning in 1929, when the disease was first reported, the classification of SC changed. SC were classified based on the presence or absence of epithelial membrane, pathogenesis, etc. SC are divided into true cysts, which have an epithelial membrane (SC type 1), and false cysts (SC type 2), in which the epithelial lining is absent. A separate group consisted of pseudocysts. They are usually of post-traumatic origin and are formed in the parenchyma of the spleen or subcapsularly as a result of hematoma transformation, less often – due to an abscess or infarction of the spleen [9, 11]. Depending on the presence or absence of the pathogen, SC are divided into parasitic and non-parasitic [1, 4, 5]. Parasitic SC are usually observed in endemic areas and are caused mainly by Echinococcus granulosus[1, 6, 10]. Modern classification is based on the pathogenesis of cysts and divides non-parasitic SC into congenital, neoplastic, posttraumatic and degenerative [3]. Primary SC account for 10% of all non-parasitic SC and are observed in different pediatric age groups. Most SC are asymptomatic, so they are mostly detected by accident during examinations (ultrasound, CT or MRI). In addition, they can be detected due to complications: suppuration or splenic rupture with bleeding, which requires urgent surgery [10, 12].