Asplenia in childhood may be congenital (e.g. Ivemark-syndrome) or acquired (functional hyposplenism in sickle cell disease; after splenectomy or bone marrow transplantation). Hereditary spherocytosis is the most common indication for splenectomy in childhood. Virtually every patient without spleen has a significantly increased risk of severe postsplenectomy infection (mostly caused by Streptococcus pneumoniae). Therefore, vaccinations against pneumococci, haemophilus influenzae and, under certain circumstances, meningococci are recommended. In addition a continuous prophylaxis with antibiotics should be performed for at least three years (or even longer depending on the disease) after splenectomy followed by lifelong interventional application of broad spectrum antibiotics in case of any unclear infection or high fever. This prophylaxis must be started as early as four months of age in sickle cell disease. In future the use of penicillin may be hampered by the growing resistance of pneumococci. Due to this fact the indication for splenectomy in childhood should be restricted to patients with hematologic disease (spherocytosis and other hemolytic anemias, chronic ITP etc.) and moderate to severe symptoms. It is unclear whether partial splenectomy for spherocytosis (and other hemolytic anemias) is an alternative regarding both longlasting reduction of hemolysis and prevention of severe infection. After trauma every effort should be undertaken to preserve a splenic remnant.