An outbreak of Shigellosis occurred in Ector and Midland Counties, in Texas. In Ector county, a case-control study showed an increased risk of Shigellosis associated with eating at outlets of a fast-food chain. In Midland County, illness was associated with eating at only two restaurants. Illness in Ector County was associated with eating shredded lettuce and tomatoes. The shredded lettuce served at all implicated restaurants was from one lettuce-shredding plant. The tomatoes originated from more than one source. The shredding plant investigation suggested that a food handler may have been the source of the contamination. The method of processing might have allowed cross contamination to occur.