Primary ciliary dyskinesia (PCD) is a genetic condition associated with abnormal ciliary structure and function. The prevalence is estimated at ∼1 in 12,000 to 17,000 individuals. Clinical manifestations include recurrent respiratory infections, chronic sinusitis, rhinitis, otitis media, and infertility. Common findings on chest radiography and CT imaging are hyperinflation of the lungs (97%), bronchial wall thickening (90%), segmental atelectasis (63%), and bronchiectasis (43%). The diagnosis of PCD may be delayed or missed because these nonspecific findings also are seen in other chronic respiratory diseases, such as refractory asthma, atypical cystic fibrosis, or middle lobe/lingula syndrome. Situs inversus is a useful finding when PCD is suspected, but is only present in ∼50% of patients with PCD. Diagnosis relies on a combination of clinical evaluation and electron microscopic analysis of the ultrastructure of cilia of the bronchial wall or nasal biopsy specimens.