85 patients who displayed Streptococcus pneumoniae (S. pneumoniae) bacteremia during hospitalization at the CHUV between January 1990 and December 1991 are reviewed retrospectively to reassess the importance of this pathology after the introduction in Switzerland of antipneumococcal vaccination. The data were compared with those obtained from a similar study at Lausanne between 1974 and 1978. Epidemiology, underlying diseases (present in 82% of patients), clinical findings (78% pneumonia, 8% meningitis, 14% bacteremia without detected primary focus) and mortality (31%) were comparable in the two series. There were, however, points of difference. First, the incidence of pneumococcal bacteremia increased between 20 and 40 years, affecting HIV positive patients in particular, with high mortality. Second, nosocomial pneumococcal bacteremia was relatively frequent (7%) and particularly severe, with very high mortality. Third, 17% of strains proved resistant to one or more antibiotics. Finally, use of the antipneumococcal vaccine is not widespread since only one of the 85 patients had been vaccinated whereas 82% presented a recognized indication for the vaccine. In conclusion, pneumococcal bacteremia remains frequent, involves major mortality and is more often due to resistant strains. These are important arguments in favour of vaccinating patients at risk.