Eight patients with osteomyelitis of the jaw were identified at two county hospitals over a 4-year period. Three patients (37.5%) were found to be HIV-seropositive, including two patients not previously known to be HIV-seropositive. Signs and symptoms of infection were similar in both groups of patients, and commonly included fever, pain, and swelling. Radiographs showed specific findings of osteomyelitis in one of three HIV-seropositive patients and four of four seronegative patients with chronic jaw infection. HIV-seropositive patients appeared to have a worse clinical outcome than their seronegative counterparts. We conclude that osteomyelitis of the jaw may be the presenting manifestation of HIV infection, and that careful attention and close follow-up should be applied to such patients because of their poor overall clinical response.