A limited study was carried out on six workers troubled by asthma and rhinitis after exposures to Cedar of Lebanon dust in a joinery works. Though five subjects were atopic they had had no major trouble working with a variety of woods hitherto. Cessation of exposure improved matters insofar as ventilatory capacity was within normal limits but some still noted wheeze and rhinitis periodically. Skin testing with wood extract was unhelpful as was serological testing (no specific precipitins were demonstrated) in elucidating the mechanism of the reaction. It is recommended that where a hazard exists in exposure to an organic dust the environmental hygiene requires attention and the atopic subject merits special monitoring.