Lung embolism is one of the most common causes of death during pregnancy and the puerperium. It is usually due to thrombosis of the deep leg and pelvic veins. As a result of modern imaging methods, it can be reliably diagnosed at an early stage. In some cases, special haemostaseological tests can identify congenital or acquired defects. This allows an initial assessment of the individual risk of thrombosis to be made. Body weight-dependent anticoagulation therapy with heparin is the major medication-based treatment. Compression treatment can be administered if accepted by the patient.