The annual incidence of paediatric venous thromboembolic disease is estimated to be 0.07–0.14 per 10000 children. In childhood, there are two age‐related peaks: neonatal period and adolescence. Idiopathic thrombosis is rare; at least one risk factor is present in more than 95% of paediatric patients. Risk factors can be acquired, including central venous catheters, cardiac disease and antiphospholipid syndrome, or be congenital, including factor V and II mutation. The need to screen for congenital risk factors is still unknown. The clinical diagnosis depends on the location of the thrombi. The majority of thrombi are catheter related and therefore situated in the upper venous system. As the clinical diagnosis lacks sensitivity and specificity, objective diagnostic imaging is necessary to establish or rule out the presence of venous thromboembolic disease. For evaluation of the upper venous system, both ultrasonography and venography are required. To detect lower extremity thrombosis, ultrasonography is an adequate method. Pulmonary embolism can be diagnosed by multidetector computed tomography or ventilation–perfusion lung scintigraphy. Prophylactic anticoagulation can be considered in certain paediatric patient groups, especially children with long‐term parenteral nutrition. Anticoagulation is the main therapy for acute thrombosis in paediatric patients. In selected patients, thrombolytic therapy can be administered. Direct mortality ranges from 0 to 4.2%, recurrent thrombosis occurs in 7–21% and the post‐thrombotic syndrome develops in 3–77% of children after venous thrombosis. In future, collaboration will be essential to establish multicentre randomized controlled trials in order to increase our knowledge about the management of paediatric thrombosis.