Random ciliary orientation was recently described as a possible variant of primary ciliary dyskinesia (PCD). The cilia have normal ultrastructure and nearly normal ciliary beat frequency (CBF) but lack efficacy because the beat direction is disoriented. However, delayed mucociliary clearance (MCC), transitory changes in ultrastructure, and slowed CBF can all occur in the presence of inflammation. This study investigated groups of patients with upper respiratory tract inflammation caused by infection to assess whether ciliary disorientation was present and its relation to MCC. The study population consisted of 10 healthy nonatopic nonsmoking volunteers, 15 patients with idiopathic bronchiectasis and chronic mucopurulent sinusitis, 12 patients with cystic fibrosis, and two patients with the clinical features of PCD but normal CBF and ciliary ulstrastructure. Ciliary disorientation was significantly (p < 0.05) increased in the three patient groups compared with the volunteers, being greatest in the two patients with the clinical features of PCD and in bronchiectasis patients with P. aeruginosa, and was positively correlated (r = 0.9) with MCC but not with CBF. Treatment of one patient with antibiotics and topical corticosteroids for a prolonged period resulted in ciliary disorientation returning to normal. Ciliary disorientation may therefore occur secondary to inflammation caused by infection, and the study suggests that ciliary disorientation rather than ultrastructural abnormalities or slow CBF results in delayed MCC.