Since avascular necrosis of the bone was first described in a HIV infected patient in 1990, its incidence has increased, especially in recent years. The hip is most commonly involved and often bilaterally. We report a series of 5 cases of avascular necrosis of the bone in patients with HIV infection. Both hips were involved in 4 of the cases. All of them were receiving highly active antiretroviral treatment when avascular necrosis of the bone was diagnosed, and 4 of them presented at least one risk factor. The risk factors found in our series were: hyperlipidemia, use of corticosteroids and alcoholism. We cannot rule out antiretroviral treatment as a risk factor for avascular necrosis of the bone. Case-control studies published have not identified antiretroviral treatment as a risk factor probably due to small size of the samples.