Escherichia coli was isolated from 58% (11/19) of retail soft and semi-soft cheeses tested, but E. coli O157:H7 was not detected. The presence of E. coli in retail cheeses and the lack of baseline data on the prevalence of serotype O157:H7 strains prompted us to survey ingredients and the environment in 15 cheese and dairy plants. Escherichia coli O157:H7 was not detected in any of the 1104 samples tested, including 42 raw milk samples. These results suggest that serotype O157:H7 is not prevalent within dairy product ingredients and processing environments.