Three persons who ate at the same Duluth restaurant on different days in early May became ill with the same strain of Salmonella Heidelberg. As a part of the investigation, food workers were required to submit stool samples for analysis. Two food workers were found to be infected with the same strain of Salmonella Heidelberg. One of these food workers reported becoming ill on May 31 after the case patients had become ill; the other food worker denied ever having any illness symptoms. Three other food workers had negative stool cultures yet reported illness in either themselves, or a family member, with dates of illness onset ranging from sometime in April to June 1. The restaurant inspection revealed numerous violations of time-temperature standards. After failing to correct food code violations found on inspection, the restaurant was closed for 10 days in mid June. No specific foods were found to be associated with illness; however, ill food workers and foodhandling violations were identified and likely led to this outbreak.