Introduction: People with a learning disability are members of a stigmatised group and research has shown that stigmatisation can have a negative impact on psychological wellbeing. The process of social comparison has been shown to be important in the experience of stigmatisation and has been shown to have been used by people with a learning disability. This thesis aims to examine the perception of stigma in people with a learning disability and the relationship it has with their psychological wellbeing. The process of social comparison in this population will be explored and the possible moderating effect it may have on the relationship between stigma and psychological wellbeing will be investigated. Methods: The study involved a questionnaire-based interview with 43 adults with a mild to moderate learning disability who attended local adult resource centres. Participants completed four self-report measures of perception of stigma, self-esteem, symptoms of psychological distress and social comparison. The social comparison measure was completed twice: once in comparison with other service users and again in comparison with people in the community. Results: Correlational analyses revealed significant relationships between perception of stigma and self-esteem and symptoms of psychological distress. Perception of stigma was shown to be significantly related to negative social comparisons, and negative social comparisons were significantly related to low self-esteem and high symptoms of psychological distress. No difference was found between social comparisons made with other service users and those made with people in the community. Social comparison was not found to have a moderating effect on the relationship between stigma and self-esteem. Discussion: The results provide further evidence that greater awareness of stigma is related to lower self-esteem, higher psychological distress and more negative social comparisons. Furthermore, those that compare themselves negatively to others report lower self-esteem and higher psychological distress. Although there was no difference in the way people with a learning disability compared themselves to their peers versus the general population, the way they see themselves compared to others in general has implications for their wellbeing. The significance of this and the relevance for future research is discussed.