Two facilities where eggs were processed were surveyed to determine the prevalence of IgE-mediated occupational asthma. Liquid egg products were produced at both sites and dried liquid products were produced at one, possibly exposing workers to egg aerosols. Area samples of ambient air were collected and analyzed for acid gases and total and respirable protein. Questionnaires were administered to all employees to identify possible cases of asthma; in addition, employees received a physical examination including pulmonary function testing and a egg allergen test panel with determination of IgE antibody by radioallergosorbent test (RAST). Ambient acid gases, chloride ions, total and respirable protein were well below the OSHA permissible exposure limit at both facilities. A total of 188 employees completed a medical survey questionnaire; 58 reported a history of wheezing or dyspnea. A total of 37 were determined on physical examination to have occupational asthma, 35 of whom complained of respiratory symptoms. Fifty one others were diagnosed with nonoccupational asthma, of whom nine complained of such symptoms. Peak expiratory flow rates were affected by symptoms in 18 of the 37 with occupational asthma and one of the 51 with nonoccupational asthma. Skin tests were performed in 86 workers; 29 were positive for an egg protein allergen. RASTs were correlated in those with positive skin tests. A total of 14 participants who reported work related symptoms on the questionnaire, who were diagnosed by the physician to have occupational asthma, and who had at least two positive skin test to egg proteins, were considered to have egg asthma. No association between atopy and egg induced asthma was found. The authors conclude that workers involved in liquid and powdered egg production are at risk for developing occupational asthma.