Introduction: There is evidence of high rates of psychopathological disorders such as anxiety or depression in adults with Down syndrome. Additionally, difficulties in executive functions and emotion regulation play an essential role in adaptive functioning of people with Down syndrome. Method: We used different questionnaires with a sample of 42 adults with Down syndrome (aged 18-40 years) to determine if difficulties in executive functions and emotion regulation are related to and can predict internalising symptoms. Results: Positive and significant correlations were found between dysexecutive functioning and emotion dysregulation and internalising symptoms. Multiple linear regression analyses indicated that dysexecutive functioning and emotion dysregulation are both predictors of the existence of internalising symptoms. Conclusions: These findings suggest that intervention in emotion regulation and executive functions must be taken into account in order to positively influence the presence of internalising symptoms. Further research is needed to attend to both capacities comprehensively, especially concerning emotion regulation.