Adenovirus–polylysine–DNA complexes were evaluated for their capacity to accomplish direct in vivo gene transfer to airway epithelium employing a rodent model. Binary complexes containing transferrin or adenovirus, or combination complexes containing both transferrin and adenovirus, were evaluated. The highest in vitro gene transfer efficiency in primary cultures of airway epithelial cells was accomplished by the combination complexes. This result was paralleled in vivo. Transient gene expression of up to 1 week was observed with localization of the transduced cells to the region of the small airways. These results establish the feasibility of this type of approach for gene therapy applications.