Despite having one of the highest smoking rates among men, information about secondhand smoke (SHS)exposure among Korean adults is lacking. This study describes SHS exposure among Korean men and women.The results were derived from a population-based, cross-sectional telephone survey conducted with 332 adultnonsmokers in Seoul. Sixty-eight percent of nonsmokers were exposed to SHS during a typical day. Exposurewas most common in locations other than home and work, where 57% of respondents were exposed, comparedto 26% at home and 25% at work. However, among those exposed, the greatest dose of exposure occurred atwork (9 cigarettes/day), followed by at home (6 cigarettes/day). Men were more likely to be exposed to SHS atwork than women. For men, lack of home smoking bans and strong belief in traditional Korean values wereindependently associated with SHS exposure in any location. For women, younger age, family members’ smoking(non-spouse), and having fewer sources of anti-SHS messages were independently associated with SHS exposureanywhere. The results highlight the need for strong, comprehensive SHS control measures, such as a completeban of smoking in all workplaces and public places, as well as public health campaigns to promote home smokingbans and non-smoking norms.