Asplenia is found in a very heterogeneous group of patients with a wide range of age and comorbidities. These patients have an increased risk of overwhelming post-splenectomy infections (OPSI) even several decades after splenectomy. The mortality rate associated with OPSI is 30 - 60 %, which is why the immunisation against encapsulated bacteria is mandatory. In addition these patients show an increased risk of thrombosis of the portal venous system. In the present article all the necessary, during daily practice often neglected preventive measures and behavioural rules are discussed.