Although many international and South African studies have investigated teenage parenting, they have rarely viewed the parenting support given to teenage mothers from a coparenting perspective. Coparenting is defined as the manner in which caregivers who are responsible for the upbringing of children, work together in their role as parents to negotiate the child rearing process. Consequently, much of the literature on teenage parenting remains inconclusive in terms of the beneficial nature of parenting support. In South Africa, very little is currently known about the availability of parenting support to teenage mothers from members of the extended family or from the child’s father and about the quality and processes that underlie these parenting relationships. A considerable body of evidence has found the quality of this relationship to be an important facilitator of parenting competence and a predictor of child development outcomes. Coparenting theory and constructs have largely been developed within nuclear, Western family structures that limit their generalizability and applicability to other family systems and contexts. Using a synergistic mixed methods research approach, this study examined the coparenting arrangements and relationship quality of 36 teenage mothers. Quantitative and qualitative data from the teenage mothers, their coparents and key community informants were used to understand coparenting within a particular low-income community where teenage parenting was found to be prevalent. The results revealed that the majority of teenage mothers could identify at least one coparent. A multi-person coparenting arrangement –typically coparenting with both the grandmother and the child’s father – was found to be more common than coparenting with only one other person. The newly developed, multi-domain measure of coparenting quality indicated that teenage mothers’ relationship with coparents was supportive, with minimal conflict and undermining by coparents. Qualitative differences in the roles of coparents revealed that coparenting fathers took on more traditional roles as providers and decision makers in comparison to grandmothers, who mainly performed mentoring roles to facilitate the teenage mothers’ maternal competence. The implications of these findings for coparenting theory as well as interventions and policies related to teenage parenting are discussed.