Six Polynesian children aged 8-14 years with recurrent lower respiratory infections and abnormal lung mucociliary clearance were assessed for immuno-deficiency. Measurements were made in these 6 children and in 21 healthy Polynesians of serum immunoglobulins (IgG, IgM, IgA) and complement components (C3, C4), leucocyte function tests, and T and B cell populations. A further 8 Polynesian bronchiectatics were tested for sputum secretory-IgA. There was no evidence of S-IgA deficiency and 4 had high levels. There was no evidence of immunodeficiency. Nasal epithelium was obtained from 6 children using a cytology brush and ciliated epithelium was obtained in only 4. The ultrastructure was normal although few cilia were examined.