This study evaluated the effect of Taiwan's smoke-free ordinance and media campaigns on public awareness and secondhand smoke exposure. The authors conducted 3 waves of research--in July 2008 (before media campaigns), in December 2008 (during media campaigns), and in March 2009 (3 months after implementation of the smoke-free law). National representative samples of 1074, 1084, and 1094 people, respectively, were interviewed successfully by telephone in the 3 surveys. The results showed that general awareness of smoke-free workplace legislation rose dramatically from 28.5% in July 2008 to 87.6% in December 2008 to 93.6% in March 2009. Exposure to secondhand smoke in the workplace fell from 28.5% in July 2008 to 24.9% in December 2008 to 7.3% in March 2009, and household secondhand smoke exposure decreased from 36.8% to 34.3% to 21.3%, respectively, during the same period. Multivariate analyses results indicated that media campaigns, smoke-free ordinance implementation, having higher education, and having higher income were associated with more awareness of the smoke-free workplace legislation. In addition, smoke-free ordinance implementation, being female, having higher education, and having higher income were associated with less likelihood of reporting secondhand smoke exposure in the workplace. In conclusion, smoke-free ordinance implementation and media campaigns were effective in raising public awareness of the new law and reducing secondhand smoke exposure in workplaces, in public places, and at home.