In 2010 public health investigators in Washington investigated an outbreak of Listeria monocytogenes in two persons whose only common exposure was sushi at Restaurant "A". One person lived in King County and was ill in June 2010. The second person lived in Pierce County and had onset in July 2010. Public Health Seattle King County conducted an inspection at Restaurant "A" and found several food handling violations. A specimen from a bamboo mat was positive for LM with an indistinguishable strain by PFGE to the strain isolated in the two patients. Three additional patients (2 in 2008 and 1 in 2011) were PFGE matches to the "sushi" strain. All three reported eating at Restaurant "A" prior to symptom onset.