From the patients’ environment, a total of 4.5% of samples from sanitary equipment and 20% of samples from surface cleaning equipment were found to be contaminated with P. aeruginosa. It was found that cleaning staff had used cleaning solution instead of disinfectants for decontamination of the patients’ environment. The outbreak stopped after re-adoption of surface disinfection, application of sterile filters on taps and shower heads and chemical disinfection of the washbasin drains. J Hosp Infect 2002;52:93-98.