An "epidemic" of polymer-fume fever involved 36 of 61 employees in one industry over a 90-day period. All of those involved demonstrated the classic history of an influenza-like syndrome, with fever and chills occuring several hours after exposure to the products of pyrolysis of polytetrafluoroethylene (Teflon). The majority of cases resulted from the smoking of cigarettes which were contaminated with a fine dust of this material. A study of pulmonary function of all workers involved demonstrated changes that could be accounted for only on the basis of smoking habits. Three persons experienced changes in pulmonary function consistant with mild obstruction of the airways, in association with the onset of symptoms. While no serious consequences were observed, the effects of these illnesses upon the health and productivity of the group could have been prevented.