We present the results of splenectomy in 45 patients with haematological diseases during the period 1975-85. Of 16 patients with immunologic thrombocytopenia, splenectomy resulted in a satisfactory and sustained platelet elevation in 11 (69%). Splenectomy corrected anaemia in all five patients with hereditary spherocytosis. Of seven patients with autoimmunohaemolytic anaemia, four responded satisfactorily. Postoperative complications occurred in ten of 45 patients (22%). There was no post-operative mortality. Only 49 per cent of the patients had received antipneumococcal vaccination. This is not satisfactory, and all unvaccinated, splenectomized patients should be offered vaccine. If possible, the vaccination should be performed before operation.