A carding machine operator in a synthetic fabric plant experienced marked symptomatic deterioration of obstructive pulmonary disease after multiple episodes of an occupational inhalation fever. Polytetrafluoroethylene was used in the industrial process and polymer fume fever is suspected as a cause of his febrile illnesses. A state industrial hygiene inspection revealed that major repairs had been performed on an air scrubber system in close proximity to the patient's work area after he had left the plant because of disability. We believe that this case provides further evidence that polymer fume fever is not always a benign, self-limited illness, especially when workers suffer multiple episodes and/or have underlying pulmonary disease.