Venous thromboembolic events (VTE) occur in children at the time of surgery. Few guidelines about how to assess the risk and provide prophylaxis have been developed and published so far. It is uncertain if any of these guidelines have been adopted into clinical practice. The article discusses the specific differences of the haemostatic system throughout childhood, risk assessment, choice and dosing of antithrombotic agents, difficulties in drug monitoring and side effects of treatment including HIT. Current available recommendations and guidelines are summarized. Current evidence on which to base risk stratification and prevention of VTE for children undergoing surgery consists mainly of cohort studies, case series, case reports and expert opinion. Many suggestions are merely extrapolated from results from clinical trials in adults. Primary healthy children who undergo minor surgery including circumcision, herniotomy and appendectomy do not need antithrombotic prophylaxis. Children with multiple risk factors for VTE including severe underlying conditions and long-term immobilization, children with central venous lines and children with a history of VTE should be considered to receive VTE prophylaxis. Older children (Tanner II+) should be treated following adult guidelines. Standard unfractionated heparin and low molecular heparin are the most frequently recommended antithrombotic drugs. Decision for VTE prophylaxis must widely be based on individual risk assessment by experienced physicians. Newly developed scores and guidelines may provide assistance. Well designed clinical studies in children that provide proper evidence on risk assessment for VTE at the time of surgery and investigate safety and efficacy of antithrombotic prophylaxis/treatment are urgently needed.