This report concerns a prolonged restaurant-associated outbreak of infection caused by a multidrug-resistant (ASSuT) strain of Salmonella Typhimurium, phage-type U302, which took place during July and August 2003 and affected people from Denmark and neighbouring countries who had attended a specific restaurant. The outbreak comprised 67 laboratory-verified cases and ten probable cases; however, the actual number of patients was estimated to be more than 390. The outbreak strain was isolated from a buffet which was probably contaminated by an assistant chef who was found to excrete the epidemic strain. An attack rate of 7.3% was estimated and long incubation periods were observed, including one extreme instance of 27 days. This outbreak underscores the importance of conscientious personal hygiene, including frequent washing of hands, for professionals handling food.