The purpose of this study was to describe coping in mothers of adolescents with type 1 diabetes and to examine the association among mothers' diabetes-related stress and coping strategies and maternal psychological distress (e.g., symptoms of anxiety and depression), adolescent adjustment (e.g., symptoms of depression, quality of life), diabetes-related family conflict, and glycemic control. One hundred and eighteen mother-adolescent dyads completed measures of diabetes-related stress, coping, symptoms of anxiety and depression, quality of life, and family conflict. Data on glycemic control were collected from adolescents' medical charts. Single/divorced mothers and mothers of color were significantly more likely to use disengagement coping strategies (e.g., avoidance) than White and married/partnered mothers. Mothers' use of primary control coping (e.g., problem solving) and secondary control coping (e.g., acceptance) strategies was related to fewer symptoms of anxiety (r = - .51, -.39) and depression (r = - .32, -.37) and less family conflict (r = - .22, -.30, all p < .05). Mothers' use of disengagement coping strategies was related to greater symptoms of anxiety (r = .30) and depression (r = .27, both p < .01). Further, secondary control coping was found to mediate the relationship between diabetes-related stress and maternal symptoms of anxiety and depression. Maternal coping was not significantly associated with adolescent outcomes. The ways in which mothers of adolescents with type 1 diabetes cope with diabetes-related stress are associated with psychological distress and family conflict. By identifying and improving mothers' coping through screening and targeted interventions, we may have the potential to improve both maternal and adolescent outcomes.