The development of prolonged obstructive airways disease after smoke inhalation is of concern to fire victims and fire fighters. Three cases of asthma that developed following the inhalation of pyrolysis products are presented along with a review of previous reports of airway injury from smoke inhalation. Polyvinyl chloride pyrolysis products seem to pose a high risk, but other toxic inhalants are also implicated. There is substantial evidence that prolonged airway hyper-responsiveness and asthma may follow numerous inflammatory insults including smoke inhalation. Studies to identify specific individual risk factors and asthmagenic pyrolysis products are needed. Early, postexposure anti-inflammatory treatment may modify the outcome.