Although divorce is relatively common, there is little research on long-term predictors of relationship dissolution among heterosexual married couples, and even less on same-sex couples. The present study examined longitudinal predictors of relationship dissolution among male–male couples, female–female couples, and heterosexual married couples over a 12-year period. Women in same-sex relationships were more likely to have dissolved their relationship than were men in same-sex couples and heterosexual married couples. There were no differences in dissolution rates between same-sex couples who had legalized their relationship and those who had not. Being in a shorter relationship, reporting lower relationship quality, and having had sex outside the relationship predicted dissolution; other factors predicted dissolution among same-sex female and heterosexual couples but not male–male couples.