Immunoglobulin levels and antibody titers were determined in bronchoalveolar (BA) lavage fluids, nasal washings, and sera from volunteers immunized with a commercial inactivated influenza virus vaccine by aerosol or subcutaneously. The IgG:IgA ratio of BA secretions was 2.5:1, thus being intermediate between the ratio in sera and nasal washings. Little albumin was found in the BA fluids. BA antibody was best stimulated by local (aerosol) immunization, was found in the IgG, as well as IgA class of immunglobulins and was locally produced.