The knowledge and skills of physicians were evaluated regarding some practical details of the usage of bronchodilators administered by canister nebulizers to determine the need for specific physician instruction in the correct usage. Fifty-five house officers and nonpulmonary attending staff from the Department of Medicine were interviewed individually. Each physician was handed a placebo canister and asked a series of standard questions regarding the recognition, assembly, and correct inhalation technique of the device. Correct assembly of the device was performed by 68 percent and 36 percent of house officers and attending staff, respectively. Only 40 percent of the participants correctly performed more than four of the seven steps felt to constitute a correct inhalation maneuver. The results reveal inadequacies in physicians' knowledge of the correct technical usage of canister nebulizers and suggest that greater attention be paid to instructing physicians in the correct inhalation technique if their role in patient education is to be effectively realized.