To study the clinical characteristics and diagnosis of primary ciliary dyskinesia (PCD). Four cases diagnosed as PCD by cilia electron microscopy examination from Jan. 2007 to Aug. 2009 in this hospital were retrospectively analyzed, and the related literature was reviewed. In the 4 patients, there were 1 male and 3 females. The age at disease onset was 0 - 10 years, and the age at diagnosis was 15 - 53 years. The most common symptoms were productive cough (4/4), sinusitis (3/4), and shortness of breath (3/4). Other manifestations included situs inversus (2/4), infertility (1/4), and tympanitis (1/4). Hypoxemia was found in 3 cases. Obstructive ventilatory impairment accompanied with diffusion dysfunction was observed in 2 cases, while the pulmonary function tests were normal in the other 2 cases. All 4 cases received chest CT scan, and bronchiectasis was present in all of them. Bilateral diffuse micronodules and patchy infiltrates were found in 3 and 2 cases respectively. Electron microscopic examination of the endobronchial biopsy specimen showed lack of dynein arms in 4, lack of muco-cilia in 2, and abnormal arrangement of microtubules in 2 cases. The Kartagener syndrome is relatively easy to be diagnosed, because it is characterized by the triad of sinusitis, bronchiectasis and situs inversus. However, PCD without situs inversus often goes unrecognized. PCD should be considered in patients with childhood onset disease, bronchiectasis, centrilobular micronodules or tree-in-bud signs in CT scan. Examination of the ciliary ultrastructure is essential to the confirmation of the diagnosis.