The tobacco industry recommends "common courtesy" as the solution to potential conflicts over smoking in public places and as an alternative to policies that restrict or ban smoking. Specifically, the industry suggests that nonsmokers "mention annoyances in a pleasant and friendly manner" and that smokers ask others, "Do you mind if I smoke?" We analyzed data for 22,000 adults who responded to the 1987 National Health Interview Survey of Cancer Epidemiology and Control to determine if common courtesy is being used in passive-smoking situations. Almost half (47%) of smokers said they light up inside public places without asking if others mind. When someone lights up a cigarette inside a public place, only 4% of nonsmokers ask the person not to smoke despite the fact that most nonsmokers consider secondhand smoke harmful and annoying. We compared these data with similar data collected by the Roper Organization in the 1970s and found that smokers today are less likely to smoke inside public places. However, nonsmokers' actions in response to secondhand smoke have changed very little. These findings show that the common courtesy approach endorsed by the tobacco industry is unlikely, by itself, to eliminate exposure to environmental tobacco smoke. Though no one would oppose the use of common courtesy, we conclude that legislative or administrative mechanisms are the only effective strategies to eliminate passive smoking.