Two cases of venous thrombosis and pulmonary embolism during or after intercontinental air travel occurring in two sisters with venous thromboembolic risk factors are presented. In one the outcome was fatal. In the present era of mass tourism the probably underestimated risk of thromboembolism in air travel should be kept in mind. As prophylactic measures leg exercises, walking and high fluid intake during the flight are recommended. Sleeping in the sitting position should be avoided. For persons at high risk, prophylactic anticoagulation may be considered.