Coparenting is associated with child behavior in families with heterosexual parents, but less is known about coparenting among lesbian- and gay-parent families. Associations were studied among self-reported divisions of labor, coparenting observations, and child adjustment ("M[subscript age]" = 3 years) among 104 adoptive families headed by lesbian, gay, or heterosexual couples. Lesbian and gay couples reported sharing child care, whereas heterosexual couples reported specialization (i.e., mothers did more child care than fathers). Observations confirmed this pattern--lesbian and gay parents participated more equally than heterosexual parents during family interaction. Lesbian couples showed the most supportive and least undermining behavior, whereas gay couples showed the least supportive behavior, and heterosexual couples the most undermining behavior. Overall, supportive coparenting was associated with better child adjustment. (Contains 5 tables.)