This article focuses on the legal and ethical aspects of management of the patient with occupational or environmental asthma. Two case studies are used for illustration purposes. The first case involved a 29 year old baker referred for wheeze and shortness of breath and a history of asthma since the age of 5 years. The second case involved a 55 year old man referred by his attorney. The man had a history of dyspnea on exertion after climbing less than 1 flight of stairs, constant wheeze, and daily cough and sputum production for 2 years. In both patients the symptoms were temporally associated with work. Both had partially reversible airways obstruction. In each case the examining physician must make decisions regarding diagnosis, medical treatment, and short and long term management. Two kinds of legal remedies are available: workers' compensation and toxic tort remedies. The two differ in basis for recovery; method of adjudication; and potential monetary award. The physician must determine diagnosis and nature and extent of impairment; determine causality with a reasonable degree of medical certainty; provide written opinions; provide examining physician or expert witness testimony; and facilitate workplace evaluation and toxic exposure control where indicated. Ethical issues revolve around determination of causality and willingness to advocate for the perceived truth, both in the legal and regulatory arenas or in the workplace.