A retrospective survey of the occurrence of pneumococcal septicaemia and meningitis in splenectomized adults was performed at a regional haematological centre after the introduction of pneumococcal vaccination in 1978. During this period 4 episodes of pneumococcal septicaemia were observed in 3 vaccinated, splenectomized patients. In all episodes the pathogenic strain was of an unusual serotype not included in the vaccine lending indirect evidence for the clinical efficacy of the pneumococcal vaccine, even in immunocompromised patients.