Human infection with Pasteurella multocida is the leading cause of animal bite wound infection. Life-threatening infection may occur in patients with a variety of underlying disorders and an immunocompromised state. Infective endocarditis with P. multocida is very rare and only a few clinically diagnosed cases have been reported. Described here is an autopsy case of a 61-year-old man with polycystic kidney disease who had P. multocida bacteremia and acute infective endocarditis with multiple bacterial clumps involving bicuspid aortic valve. The organisms were gram negative. Apparently the sepsis with P. multocida was acquired via licking of leg ulcers by his pet dog, establishing an animal-related causal relationship. Because P. multocida is a very common flora of many animals, infection with this organism probably occurs more frequently than is commonly appreciated. High index of suspicion and early diagnosis, especially in immunocompromised patients, are warranted because the disease is potentially life threatening, yet is a readily treatable infection.