Background: Studies of people with developmental disabilities suggest that participation in leisure activities might be a key factor for good quality of life. This study explores the relationships between objective and subjective quality of life and leisure participation of adults with developmental disabilities. Materials and Methods: A cross-sectional design was used with a convenience sample of 125 people, aged 17-65, living in the community. Participants completed the subjective scale of Integral Quality Scale and the Leisure Assessment Inventory in the form of an individual interview. Staff completed the GENCAT Scale. Results: No relationship was found between objective quality of life and leisure participation. However, correlations between some leisure participation dimensions and specific subjective quality of life domains were observed. The results establish a predictive relationship between leisure participation and material, emotional, and physical well-being. Personal and environmental variables analyzed were not found to have a moderating effect on the relationship between leisure participation and quality of life. Conclusions: These findings indicate that some aspects of leisure participation may significantly contribute to enhancing the quality of life of young people and adults with developmental disabilities living in the community.