A sufficiently psychometrically robust measure of community and leisure participation of adults with intellectual disabilities was not in existence, despite research identifying this as an important outcome and a key contributor to quality of life. The current study aimed to update the Guernsey Community Participation and Leisure Assessment (GCPLA). Adults with intellectual disabilities, carers and experts were consulted in creating a revised pool of 46 items. These were then tested and data from 326 adults with intellectual disabilities were analysed for their component structure and psychometric properties. Principal component analysis discovered a stable set of components describing seven different clusters. This revised measure (the GCPLA-R) was demonstrated to have satisfactory reliability, and scores were related to challenging behaviour and adaptive behaviour in theoretically consistent ways and were correlated with scores on comparable measures.