Lower airway symptoms in 27 patients with primary ciliary dyskinesia (Kartagener's syndrome, "immotile cilia syndrome") are presented. Nine of the patients had reduced ciliary beating (defective dynein arms), ten asynchroneous ciliary beating pattern (7 spoke defects and 3 other microtubular abnormalities) and eight a newly described type of abnormal bearing "hypermotile cilia" (normal cilia ultrastructure). Seventeen (63%) had partial or total situs inversus. All had absent or markedly reduced mucociliary transport in the nose and chronic rhinosinusitis since early childhood, whereas lower airway symptoms had a tendency to start later on in life. This was especially found in patients with hypermotile cilia, who also had less pronounced pulmonary disease. The most characteristic feature of the disease was a slow chronic course with a daily productive cough. Half of the patients were not even affected in their daily activities. Fifteen (56%) had bronchiectasis, and atelectasis occurred in 12 (44%). With a few exceptions the lung function was normal or only slightly reduced. Haemophilus influenzae was the most common pathogen found in sputum, but some had chronic pulmonary pseudomonas or coli infection. Improvement was seen in the patients who were regularly given antibiotics and prophylactic treatment against mucus accumulation.