A Salmonella enterica Serotype Montevideo is described that harbors DHA-1, a plasmid-mediated AmpC beta-lactamase. The organism was isolated from blood and stool specimens of a 3-yr-old girl. The isolate was multi-drug resistant, including cefoxitin, gentamicin, piperacillin, cefuroxime, ceftazidime, and cefotaxime, and an antagonism was observed between cefoxitin and oxyiminocephalosporins. The resistance to ceftazidime and cefotaxime was transferred by conjugation to the recipient E. coli J53. To our knowledge, this is the first description of Salmonella enterica Serotype Montevideo harboring DHA-1.