Between Tuesday, September 1, 2015, and Wednesday, September 2, 2015, the health surveillance and emergency response platform of the Haute-Normandie Regional Health Agency (ARS) received reports of three suspected cases of Salmonella-related foodborne illness outbreaks involving families. These foodborne illness outbreaks were reported by private laboratories in the same geographic area of the Seine-Maritime department (76). Initial investigations revealed that each of the three families had consumed artisanal ham purchased from the same deli in the 24 to 48 hours preceding the onset of symptoms in the reported cases. Epidemiological, bacteriological, and environmental investigations identified a total of 68 cases, including 6 biologically confirmed cases. The results of the cohort study indicate an association between the consumption of prepared foods purchased from a deli and the risk of developing salmonellosis. Bacteriological analyses identified a strain of Salmonella typhimurium 4,12:i:- with the same crispol type (CT 797), which had rarely been identified prior to this. The veterinary investigation revealed several operational failures that explained widespread contamination of surfaces and tools within the premises and of food products produced by the deli.