Summary From January to May 2006, a nosocomial outbreak caused by a multi-drug-resistant strain of Acinetobacter baumannii (MDRAB) occurred in a multi-specialty surgical ICU (SICU). During this episode, 20 patients were colonized by an identical MDRAB strain. Despite introduction of control measures, the outbreak was only stopped after complete closure of the unit. When a second MDRAB outbreak was confirmed in the same unit in January 2009, the SICU was closed as soon as possible. This measure allowed faster control of the outbreak, which only involved seven patients and lasted for 25 days. The economic impact of the outbreak was also considerably lower; estimated costs were €202,214 in 2009 compared with €539,325 in 2006. This study found that rapid closure of the SICU, with patients cohorted elsewhere, was a cost-effective way of controlling an MDRAB outbreak.