A 39-year-old man with no prior history of underlying arthritis developed osteomyelitis and septic arthritis in his hand following a cat bite. This case illustrates the virulence of Pasteurella multocida infections associated with animal bites, particularly those of cats, whose teeth can inoculate bone directly. The onset of cellulitis caused by P. multocida infections is often rapid, and the drug of choice for such infections remains penicillin. Appropriate antibiotic therapy, however, does not always prevent complications such as those seen in this patient.