Parents of children with developmental disabilities (DD) face greater caregiving demands than parents of children without DD. There is considerable variability in parents' adjustment to raising a child with DD, however. In line with a strengths-based approach, this study explores coping strategies as potential mechanisms of resilience among mothers of adolescents with DD. This study examines the frequency with which mothers use various coping strategies and the extent to which those strategies moderate the relationship between adolescent behaviour problems and aspects of maternal well-being. Both positive and negative dimensions of well-being are explored, with maternal depressive symptoms and perceived parenting efficacy examined as outcomes cross-sectionally and longitudinally. The present study focuses on 92 mothers and their adolescents with DD. The adolescents had a wide range of diagnoses, all with continuing special needs. Data were collected from mothers through interviews and self-administered questionnaires when their adolescents were aged 15 and aged 18. A structured assessment of the adolescent was completed during home visits at age 15. Mothers reported frequently using strategies of denial and planning but rarely using strategies of mental and behavioural disengagement to cope with recent stressful situations. Adolescent behaviour problems were found to contribute to greater symptoms of depression and lower feelings of parenting efficacy as well as increases in depressive symptoms over time. Mothers of sons, but not daughters, reported increases in parenting efficacy across their child's adolescent period. Above and beyond adolescent factors, several coping strategies emerged as significant predictors of mothers' symptoms of depression and perceived parenting efficacy. Moreover, use of Active Coping/Planning, Positive Reinterpretation/Growth, and Behavioural/Mental Disengagement as coping strategies moderated the impact of adolescent behaviour problems on maternal depressive symptoms. This study extends previous findings by focusing on both positive and negative dimensions of parent well-being during their child's adolescent period. Adolescence can be a stressful time for parents, with typical developmental tasks entailing additional strains for parents of adolescents with DD. The present findings point to several coping strategies that may reduce the impact of challenging behaviours during this period on mothers' symptoms of depression and feelings of parenting efficacy. Certain coping strategies were found to exert a greater impact on maternal well-being for parents of adolescents with higher levels of behaviour problems, suggesting that interventions may benefit from an increased focus on this group of mothers with heightened caregiving demands. © 2012 The Authors. Journal of Intellectual Disability Research © 2012 John Wiley & Sons Ltd, MENCAP & IASSID.