Young adults (n = 964; never married; age, 18-27 years) in Hong Kong were surveyed to obtain information about their smoking habits and sexual behaviors. Current smokers (15% of the entire sample) and those who had ever had sexual intercourse (28%) were more likely to be male, to have ended their education at secondary school, and to report less life satisfaction. After controlling for demographic and psychosocial correlates, sexual intercourse was associated with smoking status for both males and females. Among those who were sexually active, those who had multiple sexual partners, had their first sexual experience prior to age 18 years, and (for males) reported visiting massage parlors were more likely to have a history of smoking. Our findings extend those of our previous study with community adolescents in Hong Kong and suggest that smoking may be a marker for other high-risk behaviors among young Chinese adults.