Background: The aim of the study was to explore the validity of the social-moral awareness test (SMAT) a measure designed for assessing socio-moral rule knowledge and reasoning in people with learning disabilities. Comparisons between Theory of Mind and socio-moral reasoning allowed the exploration of construct validity of the tool. Factor structure, reliability and discriminant validity were also assessed. Materials and Methods: Seventy-one participants with mild-moderate learning disabilities completed the two scales of the SMAT and two False Belief Tasks for Theory of Mind. Results: Reliability of the SMAT was very good, and the scales were shown to be uni-dimensional in factor structure. There was a significant positive relationship between Theory of Mind and both SMAT scales. Conclusions: There is early evidence of the construct validity and reliability of the SMAT. Further assessment of the validity of the SMAT will be required. (Contains 5 tables and 3 pictures.)