PURPOSE: To determine the clinical and radio-graphic characteristics of sinusitis in patients with human immunodeficiency virus type 1 (HIV-1) infection. PATIENTS AND METHODS: A retrospective study was performed that identified all HIV-1-infected patients with sinus radiographs, sinus computed tomograms, or magnetic resonance imaging of the head between 1982 and 1989 (n = 145). Medical record review detailed the clinical course and laboratory parameters in all patients. RESULTS: Eighty-nine patients had radiographic evidence of sinusitis; 75 patients had adequate clinical data and comprise the study group. Acute sinusitis was seen in 10 patients (13%), while all 75 patients had mucosal thickening indicative of chronic sinusitis. Fifty patients (67%) were symptomatic with fever, nasal congestion or discharge, and headache being the most common symptoms; nineteen patients (25%) were asymptomatic when their radiographs showed active disease. The mean CD4 count for the group was 276 cells/mm3; 32 (43%) had CD4 counts less than or equal to 100 cells/mm3. Twenty-three patients (31%) received antibiotics orally, parenterally, or both. CONCLUSIONS: Sinusitis appears to occur frequently in HIV-infected patients, is often asymptomatic, may be recurrent or refractory, and may be associated with declining immunocompetence in HIV-infected patients.