This article examines marital patterns and use of mother tongue at home among native-born Asian Americans using the 2005-2007 American Community Survey 3-Year Public Use Microdata Sample. There are variations in mother-tongue use across Asian ethnic groups, but variations among different types of marriage are even greater. Those who marry within their ethnicity (in-married) have a greater likelihood of mother-tongue use at home than those who intermarry. Among the in-married, those having 1.5- and first-generation co-ethnic spouses are far more likely to use a mother tongue than those having native-born, co-ethnic partners. Results of logistic regression analyses indicate that marital patterns are the strongest predictor of mother-tongue use at home, and that ethnic variations in mother-tongue use are significantly reduced when marital patterns are taken into account. (Contains 5 notes and 5 tables.)