Public Health Seattle King County (PHSKC) investigated an outbreak of gastroenteritis among customers at Xi'an Noodles located in the University District of Seattle. Three people from a single meal party became ill after eating at the restaurant on December 21, 2018. Symptoms and timing of illness onsets suggested a bacterial toxin such as Bacillus cereus or Clostridium perfringens. No one was hospitalized and no one died. The exact food or drink that caused the illness was not identified. Environmental Health investigators visited the restaurant on December 31, 2018. Investigators identified potential risk factors for bacterial toxin growth, including incorrect cooling of potentially hazardous foods, improper storage of foods at room temperature, and lack of thermometer use to measure food temperatures.