Children with developmental disorders or disabilities often experience a wide range of difficulties and reduced quality of life. Surfing is gaining popularity as a sport that can promote psychological well-being, but research is still scarce. The current study aimed to investigate the effects of surfing on the quality of life of children with developmental difficulties. Participants were 84 children with Down syndrome, autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD). Quality of life was measured by a parent-rated questionnaire (KIDSCREEN-27) before and after a series of three adapted surfing lessons. Additionally, responses on an evaluation questionnaire were qualitatively analysed to gain more insight into the experiences of children and parents. Results of the KIDSCREEN showed a significant increase in the children's quality of life after 3 surfing lessons for the Total score, as well as subscale scores for Psychological well-being, Social support & peers and School. A trend towards significance was found for the subscale Autonomy & parent relation. Qualitative analysis of evaluation data showed consistent positive experiences by children as well as parents. According to parents, surfing improved the child's mood, self-confidence, self-esteem and social-emotional functioning. They saw their child enjoy the lessons, conquering their fears, feeling safe and free. According to many parents, effects transferred into their child's daily life. Surfing in a safe, structured and positive environment holds promise to improve the quality of life for children with developmental difficulties. Findings provide valuable insights into the scope of these effects and possible working mechanisms underlying the effects.