Although disease caused by Arizona hinshawii is known to resemble the spectrum of clinical syndromes seen with Salmonella infections, little is known of their sensitivity to antimicrobials. We present three cases that are illustrative of Arizona sepsis, localized infection, or both; review the literature; and report sensitivities to 12 antimicrobials for 32 human and animal isolates of Arizona hinshawii from various geographic areas. With the exception of erythromycin and streptomycin, most strains were sensitive to many of the commonly used antibiotics. As with Salmonella infections, ampicillin or chloramphenicol appear to be the initial antimicrobial agents of choice for severe infections with A. hinshawii. Definitive antimicrobial therapy must be individualized on the basis of sensitivity testing and with regard to host factors.