We report two cases of soybean-lecithin-induced asthma in bakers. The patients experienced clinical symptoms in relation to an occupational exposure to this additive. Skin tests were positive with soybean lecithin, RAST showed a sensitization to soybean, and bronchial challenge tests were positive for a dilution of 10(-3) with this allergen. The same tests remained negative among healthy and asthmatic controls. Soybean lecithin, a common additive in bakery, must be added to the list of numerous aeroallergens involved in baker's asthma.