As more unmarried couples become parents, it is important to understand the dynamics that help these couples to maintain strong relationships. This article explores the association of the two partners' beliefs about father involvement with their likelihood of union dissolution and transition to marriage, using the first two waves of the Fragile Families survey (n = 2,303). It finds that couples are more likely to end their union when partners do not believe that fathers' caregiving is very important and when the father participates less. Partners are less likely to marry if the mother does not believe that fathers' caregiving is very important. These effects are distinct from the quality of the couple's relationship and suggest that unmarried parents who value the father's role as a hands-on parent may be more motivated to build a stronger relationship. (Contains 3 tables.)