Background: People with developmental disabilities are at high risk for a limited participation in leisure activities. The aim of this study was to investigate the participation in, preference for and interest in leisure activities of young and adults with developmental disabilities, and to examine the factors associated with leisure activity. Methods: A cross-sectional design was used with a convenience sample of 237 people aged 17 to 65, living in the community. Leisure participation was assessed with the Spanish version of Leisure Assessment Inventory. Percentages were calculated by types of activity, and repeated measures "anovas" were used to analyse the differences between types of activities, and mixed "anovas" to analyse the factors that explain differences in leisure activity participation, preference and interest. Results: Leisure social activities and recreation activities at home were mostly solitary and passive in nature and were identified as those being most commonly engaged in. Respondents expressed preference for more social and physical activity, and they were interested in trying out a large number of physical activities. Age and type of schooling determine participation in leisure activity. The results underscore the differences in leisure activity participation, preference and interest depending on the severity of the disability. Conclusions: The findings reveal interesting patterns of participation in leisure activities from the viewpoint of youngsters and adults with developmental disabilities. Leisure participation among people with developmental disabilities is likely to be more affected by environmental factors than by personal factors. (Contains 7 tables.)