Odontoid osteomyelitis is a rare infectious disease that manifests as fever and posterior neck pain, while crowned dens syndrome is a relatively common inflammatory disorder with similar signs and symptoms. We describe the case of a 90-year-old woman presenting with fever, posterior neck pain, throat pain, and headache. Crowned dens syndrome was initially diagnosed based on the clinical picture and calcification around the odontoid process on cervical spine CT. However, the diagnosis was revised to odontoid osteomyelitis following the detection of Staphylococcus aureus in blood cultures that were performed due to the presence of headache. Infectious complications included spinal epidural abscess extending to the hypoglossal canal and osteomyelitis spreading to the clivus. Nonetheless, the patient achieved complete recovery after 13 weeks of antimicrobial therapy. No reports of odontoid osteomyelitis with calcification around the odontoid process have been reported. This case underscores the importance of avoiding a hasty diagnosis of crowned dens syndrome when calcification around the odontoid process is observed in patients presenting with fever and posterior neck pain. It is crucial to perform a thorough medical history review and physical examination to exclude other conditions. In cases where infection is suspected, blood cultures and cervical spine MRI are essential to investigate odontoid osteomyelitis and other complications.