BACKGROUND: Higher acculturation is associated with Asian-American smoking prevalence decreasing in men and increasing in women. Asian immigrants in California are significantly more likely than their counterparts in Asia to have quit smoking. Smoke-free environments may mediate this acculturation effect because such environments are not widespread in Asia. METHODS: In 2006, Asian-American current and former smokers were analyzed using the 2003 California Health Interview Survey. A multivariate logistic regression analysis examined how the interaction between having a smoke-free-home rule and immigrating to the U.S. is associated with status as a former smoker and lighter smoking. RESULTS: For recent Asian immigrants (<10 years in the U.S.) and longer-term residents (born/>or=10 years in the U.S.), having a smoke-free-home rule was associated with status as a former smoker (OR 14.19, 95% CI=4.46, 45.12; OR 3.25, 95% CI=1.79, 5.90, respectively). This association was stronger for recent immigrants (p=0.02). Having a smoke-free-home rule was associated with lighter smoking only for longer-term residents (OR 5.37, 95% CI=2.79, 10.31). CONCLUSIONS: For Asian Americans, smoke-free-home rules are associated with status as a former smoker, particularly among recent immigrants, and lighter smoking in long-term residents. Interventions encouraging Asian Americans to adopt smoke-free-home rules should be evaluated.