Several studies have employed an RFT-based test protocol as an assessment of perspective-taking with both typical and atypical samples of adults and children. In addition, other RFT protocols have found significant correlations between competencies on specific relations and outcomes on standardised IQ measures. However, there is no research to date that has examined correlations between relational perspective-taking and IQ. In the current study, 24 adults with varying levels of intellectual disability were exposed to standard measures of language ability and IQ, as well as an RFT-based test protocol for perspective-taking. In line with previous evidence, the results indicated significant differences across performances on different aspects of the perspective-taking protocol. Furthermore, the data indicated that perspective-taking correlated with verbal ability, full-scale IQ and performance IQ. These findings provide further evidence of the utility of the RFT-based protocol of deictic frames and highlight the role of intellectual functioning in perspective-taking