This study identifies how marital interaction influences the marital instability of foreign wives. Data for the study were based on a snowball sampling of 101 foreign wives married to Korean husbands in Gyeongnam, Korea. The respondents reported higher levels of perceived spousal support, marital satisfaction, and sexual satisfaction, but reported lower levels of spousal hostility. A hierarchical regression analysis was conducted to identify the variables that affect marital instability. Independent variables included in the study were years married, religion, monthly income, educational level, perceived husband support, sexual satisfaction, marital satisfaction, and perceived husband hostility. While religion, educational level, sexual satisfaction, marital satisfaction, and perceived husband hostility had a strong effects on the marital instability of foreign wives, years of marriage, monthly income, and perceived husband support did not show significant effect on marital instability. Marital satisfaction had the strongest effect on marital instability.