Nasal mucociliary transport was studied in 33 HIV-positive patients with different stages of infection. Ciliary ultrastructure was studied in 8 of these cases. At the time of study, 24 patients had respiratory infections. Disturbances in mucociliary transport were found in 25 cases. In 6 of the 8 studies of ciliary ultrastructure, changes in the ciliary axonema were found, particularly in the central and peripheral microtubules.