Achromobacter xylosoxidans contaminating transducers caused 15 cases of hospital infection. In the eight patients with bacteraemia the interval from inoculation to fever was an average of 6·6 days. All the infected patients recovered. Computerization of laboratory records allowed retrieval of previous isolates, and review of clinical records focused the problem on patients with cardiac and aortic diseases. The problem arose from the re-use of disposable equipment after disinfection with a benzalcone.