The origin of an outbreak of Enterobacter cloacae septicemia in six surgery patients was traced down to the total parenteral nutrition production line. While the endproduct of the production line was sterile, Enterobacter cloacae and other bacteria were detected on different tabs and tubings of the line. It is believed that the bacteria were transferred from the tabs to a few bags of the total parenteral nutrition in one batch by touch contamination. Serotyping and phage-typing of the clinical isolates revealed that five of the patients' strains were identical.