Little research has explored same-gender couples' experiences of relationship dissolution, and no research has explored relationship dissolution in same-gender adoptive parents. Drawing from feminist and social constructionist perspectives, the current qualitative study examined the perspectives of 13 adoptive mothers (seven lesbian, six heterosexual) who had separated from their partners over the course of a longitudinal study on adoptive families. Participants were interviewed via telephone and represented a geographically diverse sample of mothers in the U.S. Becoming a parent (to a high-needs child in particular), differences in parenting style, parent problems (e.g., substance abuse), and infidelity were perceived as contributing to relationship dissolution by all types of participants. Lesbian mothers were especially likely to emphasize problems with emotional and sexual intimacy, and inequities in the division of labor, as contributors. Lesbian mothers were more likely to describe shared custody arrangements than heterosexual mothers, who were typically the primary residential parents. Participants described both practical challenges (e.g., financial insecurity) and emotional challenges (e.g., feelings of guilt, especially in light of the child's history of loss) in the wake of relationship dissolution. However, participants also identified positive changes that had occurred post-dissolution, including personal growth and improved co-parenting, with the latter being noted by lesbians in particular. Findings have implications for professionals wishing to support diverse families during key life transitions, such as parental relationship dissolution.