Laboratory surveillance revealed two genetically matched, Shigella flexneri 2a isolates. Upon investigation into these isolates and interview of the corresponding cases, a common exposure was found. Both cases had eaten at the same Roseville, Minnesota, restaurant within two days of each other. Both cases had eaten beef tacos. An inspection found food holding temperature violations, improper storage of raw animal products and improper cleaning. No employees reported illness, but the state concluded an infected food handler was the most likely cause of the infections. A food product contaminated prior to delivery of the food at the restaurant could not be ruled out, but the small number of cases made this seem a less likely cause.