We report on ciliary aplasia of the respiratory tract, a rare disorder of the mucociliary apparatus, that is insufficiently recognized as a distinct entity. A culture method for ciliogenesis was developed by our laboratory and offers the advantage of studying cilia free of secondary changes associated with infection. Three cases of primary ciliary aplasia were documented histologically in direct biopsy specimens and also in biopsy specimens cultured specifically for ciliogenesis. Primary ciliary aplasia should be differentiated from secondary ciliary aplasia in which basal bodies are present and ciliogenesis takes place in specific culture. Only hereditary ciliary abnormalities are expressed in cell cultures. We critically review the cases of ciliary aplasia reported to date.