AIDS patients suffer from multiple immunologic deficits involving humoral and cell-mediated immunity. The humoral deficits place the patient at a higher risk for recurrent bacterial infection than the general population. Sinusitis has been recognized to be a more common problem in AIDS patients than was previously appreciated. A high level of clinical suspicion is important, especially in patients with fever, headaches, or symptoms referrable to the upper respiratory tract. Should sinusitis be demonstrated, aggressive medical management is indicated. Surgical drainage is indicated in patients who worsen in spite of appropriate medical therapy, patients who have signs of systemic toxicity from the sinusitis that do not rapidly improve, and patients with recurrent sinusitis. Further studies are indicated to determine the true incidence of sinusitis in the AIDS population and to elucidate further the immunologic defects involved.