Juvenile respiratory papillomatosis involving the tracheo-bronchial tree imposes a significant management problem and is sometimes life threatening. The mainstay of treatment is repeated vapourization with a CO2 laser. To date, adjunctive medical treatments have been of limited value. A tracheostomized child with extensive laryngo-tracheo-bronchial papillomatosis who has required bronchoscopic lasering at two-weekly intervals for three years was treated with ribavirin, a broad spectrum anti-viral agent. The drug was administered in nebulized form using a small particle aerosol generator (S.P. A.G.) to the lower respiratory tract (6 gm/150 ml over nine hours) on three consecutive nights every two weeks over seven weeks and also administered orally (15 mg/kg/day). Endoscopic assessments were made every two weeks. At 14 days the papillomata were regressing and far less lasering was required. No further lasering was required up to 56 days. One month after stopping the ribavirin, however, a few sessile papillomata in the tracheo-bronchial tree had recurred and were treated with the laser. No adverse reactions were encountered. During the treatment period there was a significant reduction in the frequency of therapeutic endoscopies. This promising response requires further evaluation to define the role of ribavirin in the treatment of juvenile respiratory papillomatosis.