Historically, most health occupations have developed legal and ethical restrictions on price advertising and other characteristics of 'commercial' practice. Many of these regulations recently have come under critical scrutiny, on the grounds that they inhibit free-market health care delivery, thus keeping prices high, and productivity and innovation low. To help inform current health policy deliberations, we analyze the political history of anticompetitive regulations in one health occupation, optometry. Restrictions on commercial practice arose as a result of professional optometry's purge of commercial elements in the 1930s. Optometry's success in achieving commercial-practice restrictions at the state level was determined by the economic structure of the opthalmic goods and services industry in each state in the 1930s, and by the political resources and organization of the competing interest groups. Efforts to deregulate health occupations will precipitate political conflict to the extent that economic interests are threatened. Opposition to deregulation will be based overtly on the grounds that quality of care will deteriorate, and a significant political investment by proponents of free-market health care will be required to overcome such opposition.