OBJECTIVES: Huntington’s disease (HD) is a rare neurodegenerative disease affecting motor, cognitive and psychological function. Data collection is difficult because of the low prevalence and the small number of specialized centers. The creation of a specific self-administered questionnaire covering various clinical aspects of the disease would make the HD-patient clinical data collection easier. Such an instrument also offers the advantage of allowing a remote follow-up and getting information on the development of motor, functional and behavioral disorders of HD patients perceived by the patient himself. The objective of this study is to validate a new self-reported clinical instrument for HD-patients. METHODS: The European HD burden study (Euro-HDB) is an ongoing cross-sectional survey among HD-patients and their caregivers in six European countries. The H-CSRI, a self-reported instrument based on the Unified Huntington’s Disease Rating Scale (UHDRS) and developed with the expertise of a neurologist and a psychiatrist, was administered. It included three subscales assessing the motor, functional and behavioural ability. Classical test theory and item response theory were used to assess its clinimetric properties. RESULTS: Among 311 patients from both Italy and France, item response rates range from 86% to 99%. There was a floor effect on items related to psychotic disorder in the behavioral subscale, because these symptoms do not affect all patients. The H-CSRI showed an acceptable reliability (Cronbach’s alphas>0.74). Factor analyses demonstrated a satisfactory construct validity. Moreover, the item internal consistency and item discriminant validity criteria were met. The differential item functioning analyses showed no item bias between the two countries and between genders. CONCLUSIONS: These data support the validity of the H-CSRI to assess the health status for patients with HD. Planned next steps include assessments of responsiveness to change, test–retest reliability and convergence between UHDRS and H-CSRI scales.