Falls from heights and traffic accidents are the most common causes of splenic damage. Abdominal trauma can cause splenic rupture or splenic vein thrombosis. About 11–55% of children with splenic vein thrombosis develop collateral circulation, leading to gastric and/or oesophageal varicose veins. Venous thrombosis in children can be also caused by congenital factors associated with coagulation disorders. The paper describes a case of a 3-month-old girl who developed isolated splenic vein thrombosis after a fall from height. Laboratory and genetic findings excluded thrombophilia. A 3-month anticoagulant treatment was administered. Gradual reduction in splenic size and the development of collateral circulation were observed in subsequent ultrasound scans. The girl remains under the care of a surgical clinic. The presented case of an infant with splenic vein thrombosis draws attention to possible complications of abdominal trauma after a fall from height.