Here, we showed our clinicopathological findings of infected aortic aneurysm (IAA) withPasteurella multocida, which is a Gram-negative coccobacillus and is part of the normal oral flora of many animals. The patient was a 76-year-old male animal owner with a history of diabetes mellitus, alcoholic liver damage, and laryngeal cancer. He died 16 days after admission without undergoing operation because of poor general condition. Autopsy showed saccular outpouching with loss of the existing aortic wall and marked neutrophilic infiltration in the suprarenal abdominal aorta. Rupture was not evident. A polymerase chain reaction assay using DNA extracted from formalin-fixed paraffin-embedded specimen of the aneurysmal wall detected thePasteurella multocidagene, therefore we conclude that the present case was IAA of native aorta withPasteurella multocidainfection. A review of the literature showed that IAA of native aorta withPasteurella multocidainfection is opportunistic and that liver disorder, alcohol addiction, diabetes mellitus, and animal bite may increase its risk. On the other hand, aortic endograft infection withPasteurella multocidafrequently occurred without an immunocompromised state.Pasteurella multocidamay be a distinct causative microorganism in IAA, and/or sepsis when the participant is an animal owner.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12941-023-00611-0.