The study presented here was conducted over a period of 4 years (2001-2004) to investigate changes in the number of S. maltophilia isolates detected per 1,000 patient days and to look at the incidence density of nosocomial infections caused by S. maltophilia. The analysis was based on data provided by 34 German intensive care units participating continuously in the national project "Surveillance of Antimicrobial Use and Resistance in ICUs"; 31 of these ICUs reported nosocomial infections to the German infection surveillance system, KISS, during the study period.