In August 2012 Minnesota public health officials investigated an outbreak of norovirus among patrons of a restaurant located in Maple Grove, Minnesota. Cases occurred among 3 different dining parties who ate at the restaurant on August 13 or August 14. Ten people met the case definition. The median duration of illness was 2 days for 5 cases who had recovered at the time of interview. Three stool specimens tested positive for norovirus GII. Nucleic acid sequencing was conducted on all three of the positive norovirus specimens. The sequences were identical. Illness histories were obtained from 79 restaurant employees. Sixteen employees reported having had a gastrointestinal illness in the past 2 weeks. Illness onsets for employees ranged from August 8 to August 19. Stool specimens were obtained from 2 employees. Both tested positive for norovirus GII. Nucleic acid sequencing was conducted and sequences were identical to each other and to the 3 patron sequences.