On April 12, 2012 the Minnesota Department of Health (MDH) Foodborne illness hotline received a complaint of gastrointestinal illness among a group of 13 individuals from 5 households who ate at a restaurant located in Willmar, Minnesota on April 8. Kandiyohi County Environmental Health Services (KCEHS) was notified and an investigation was initiated. MDH interviewed 65 restaurant patrons identified from credit card receipts about food consumption and illness history. Twenty-two people met the case definition. The median incubation period was 52.5 hours (range, 20.5 to 77 hours). The median duration of illness was 3 days (range, 1 to 5 days). Stool sample were submitted by 5 cases; three were positive for sapovirus. By univariate analysis, consuming baked ham and Swedish meatballs were significantly associated with illness. Both baked ham and Swedish meatballs remained idependently associated with illness in multivariable logistic regression. A KCEHS sanitarian conducted an on-site inspection at the restaurant on April 13 to evaluate food preparation and handling procedures and interview food workers. Two employees reported recent gastrointestinal illness. A server had worked on April 8 and reported consuming both Swedish meatballs and baked ham. A stool sample was negative. Investigators concluded this was a sapovirus outbreak associated with a restaurant in Willmar. Baked ham and Swedish meatballs were statistically associated with illness although the source of contamination was not identified. They concluded that the most plausible source of contamination was either an unidentified infected food worker or an infected patron who contaminated utensils used to serve food items.