Background: Smoke-free policies in public places have become more common in China. Little is known, however, about the potential unintended consequences of such policies on pregnant women. Methods: The study was conducted in 2006 in Chengdu, China. Nonsmoking pregnant women (N=55) whose husband were smokers participated in a study of their knowledge about secondhand smoke and smoke-free policies, their exposure to secondhand smoke, and their husbands' smoking status at home. This study presents descriptive statistics, analyses based on family income and pregnant women's education level, and the findings of focus group discussions that examined the potential unintended consequences of the smoke-free policies on pregnant women. Results: Exposure to secondhand smoke at home was reported by 69.1% of the pregnant women. Both family income and the education level of the pregnant women had a significant (p<0.05) association with exposure to secondhand smoke. The four main potential unintended consequences of the smoke-free policies were: (1) increased exposure of pregnant women to secondhand smoke at home; (2) reduced work efficiency; (3) adverse effect on family harmony; and (4) poor air quality at home. Conclusions: Education is needed to increase knowledge of secondhand smoke among smokers and nonsmokers alike. When the smoking location is shifted from public places and workplaces to home, women, and in particular pregnant women, become the victims. Policymakers should recognize such potential unintended consequences and take necessary measures to increase awareness about the harms of secondhand smoke. © 2009 American Journal of Preventive Medicine.