Objectives Many parents of children with developmental disabilities, including autism spectrum disorders and attention deficit disorders, experience poor well-being and increased anxiety and depression. Very few interventions directly target parents' needs. The peer-delivered HOPE Programme was designed to address this with six weekly group sessions focusing on self-management skills, including goal setting and expressing gratitude. Methods This pre-post study aimed to examine changes in anxiety, depression, well-being, hope and gratitude, and to explore associations between changes in anxiety and depression and changes in gratitude and hope. Validated measures of depression, anxiety, positive well-being, gratitude and hope were used. Parents of children with a range of developmental disabilities, most commonly autism spectrum disorders, were recruited. Results Of 137 (86.9% female) recruited, 108 parents completed the course and post-course data. Parents' depression, anxiety, well-being, gratitude and hope all significantly improved between baseline and post-course. Hope and gratitude correlated significantly with depression, anxiety and well-being. Baseline depression, baseline gratitude, post-course hope and gratitude explained 50% of the variance in post-course depression. Reduced work hours, and baseline and post-course hope and gratitude explained 40% of the variance in post-course well-being. Anxiety was not associated to hope nor gratitude at either time point. Conclusions This study provides initial support for feasibility and potential effect of the peer delivered self-management intervention on parental anxiety and depression. Changes in gratitude and hope account for some change in depression, but not anxiety. A randomised controlled trial is needed to establish efficacy and explore mechanisms of change in-depth. Keywords Autism spectrum disorders • Parents • Self-management • Well-being • Developmental disability Research has documented elevated levels of parental stress and distress experienced by parents raising children with developmental disorders (DD) or disabilities, such as autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), or other learning disabilities (Gordon and Hinshaw 2015; Hassall and Rose 2005; Hayes and Watson 2013; Johnston and Mash 2001). There are some specific differences between stressors reported by parents of children with different DD. For example, ADHD has been linked to greater attachment difficulties than ASD (Miranda