A 40-year-old man was admitted with a continuous high grade fever accompanying a relatively large solitary liver abscess with septations. A puncture of the abscess revealed gram-negative rods that could be identified histologically as Fusobacterium necrophorum, which was later confirmed by tissue culture. The patient was switched to meropenem and penicillin, and cured of the infection. Fusobacterium necrophorum is a rare bacterium causing potentially fatal liver abscesses in humans. Clinicians should bear Fusobacterium necrophorum in mind when treating patients with an enlarged solitary liver abscess.