A cluster of illnesses with matching strains of E. coli O157:H7 was investigated by the Centers for Disease Control and state health departments, Cluster ID #0910MAEXH-1. On October 31, a recall of over 500,000 pounds of beef products from Fairbanks Farms was issued because the product was contaminated with E. coli O157:H7. At least some of the ill had consumed the beef prior to their illness onset. Two samples of ground beef recovered from a patients' homes yielded a strain of E. coli O157:H7 that matched the outbreak strain. Most of the illnesses occurred in September and October. Fairbank Farms had recalled its ground beef previously in 2007 and 2008, one of these instances was also for E. coli contamination. This outbreak occurred concurrently with an E. coli O157:H7 outbreak associated with South Shore Meats, also affecting persons in the Northeastern United States. The last known illness associated with this outbreak began November 6.