For the first time, we report Klebsiella pneumoniae as an enteroinvasive food-borne pathogen transmitted from a hamburger. A 28-year-old previously healthy African-American male ingested a portion of a hamburger from a fast food chain. Symptoms of gastroenteritis rapidly deteriorated to multiorgan failure. Blood and hamburger cultures grew Escherichia coli and Klebsiella pneumoniae. Since Klebsiella had not previously been reported as enteroinvasive, the isolates were compared. Full biochemical profiles, antimicrobial sensitivity, plasmid profile, and toxin assay by DNA hybridization probe were completely concordant. The patient survived the episode of food-borne sepsis. Deliberate or inadvertent employee contamination of food products with feces may be a potential source of life-threatening food-borne illness.