Oklahoma public health officials investigated an outbreak of gastroenteritis among guests at a rehearsal dinner and wedding held in August 2017. The meals were served over a two day period (August 5-6). Twenty-eight people reported symptoms that included vomiting and diarrhea. A specimen collected from an ill attendee 12 days after symptoms resolved was negative for foodborne pathogens. No one was hospitalized and no one died. The rehearsal dinner was prepared in a private residence the night before the wedding. A traditional Brazilian meal was served. It was noted there were concerns with food preparation because of lack of hand washing and cross contamination.