SummaryA recent decrease in the frequency and severity of infections caused byP. aeruginosa, which had become the prototype of severe opportunistic infection, can be attributed, in part at least, to the development of new potent antipseudomonal antibiotics.However, prevention of this type of infection by the promotion of a high standard of nursing care and maybe also by the use of antipseudomonal vaccines remains the most important approach to the control of the infections caused byP. aeruginosain the susceptible patients.