Environmental tobacco smoke (ETS) poses an underappreciated risk to adolescent health. This study examined perceptions of adolescents (n = 574) regarding ETS. About one half (54%) were exposed to ETS the previous week, and one third (30%) were exposed to 3 or more hours of ETS the past week. Concurrently, 29% believed that breathing someone else's cigarette smoke had little or no effect on their health. Most adolescents (56%) believed that smoking should not be allowed in restaurants without bars but were less supportive of prohibiting smoking in restaurants with bars (20%) or in bars (14%). Two thirds (69%) of adolescents believed that the government should be involved in making laws that protect the health of people who work in bars and restaurants. Almost one half (49%) believed that the government should be involved in passing laws that make it illegal for people to smoke in public places. Odds ratios revealed that females, nonwhites, younger students, nonsmoking students, and students who believed that ETS exposure had a moderate or major effect on health were statistically significantly more likely to support clean indoor air ordinances in select locations compared to males, whites, older students, students who smoke, and students who perceived that ETS exposure has little to no effect on health.