Among 4,023 HIV-infected patients admitted to a large Italian university hospital in the period 1985-1996, 14 had concomitant HIV and bacterial osteoarticular infections. Staphylococcus aureus infections were commonest and were diagnosed in 8 patients. Intravenous drug addiction was the only risk factor significantly associated with the development of osteoarticular infection (p = 0.04). In contrast, no statistical correlations were found with age, sex, absolute number of circulating T-CD4+ lymphocytes, neutrophils and stage of HIV infection. In conclusion, osteoarticular infections are uncommon in HIV-infected patients and are more directly related to parenteral drug abuse than to HIV.