Background: There is paucity in availability of valid and reliable measures of psychopathology that can be routinely applied with an intellectual disability (ID) population in clinical practice. The psychometric properties of the Clinical Outcome Routine Evaluation-Learning Disabilities 30-Item version (CORE-LD30) are examined. Method: The CORE-LD30 was administered to 271 sequential referrals to three National Health Service (NHS) ID services providing psychological support. A principal components analysis with oblique rotation was conducted with examination of convergent validity for extracted domains. Results: Three rotated factors were extracted with good levels of internal consistency reported for the overall measure (a = 0.92) and each of the domains, conceptually labelled Problems/Symptoms (a = 0.90), Risk to Self (a = 0.76) and Risk to Others (a = 0.71). Convergent validity is reported for two domains [Problems/Symptoms with the Glasgow Depression Scale for people with a learning disability (LD) and Risk to Others with the Health of the Nation Outcome Scale-LD], and support for the CORE-LD30 as a 'core' measure indicated. Conclusions: The CORE-LD30 is recommended as a useful broad ranging measure of psychopathology for use with an ID population. Domains may prove to be useful for research and clinical purposes. Further research is recommended to examine the ability to monitor clinical change associated with specific levels of presentation and different clinical presentations/cohorts.