When planning clinical studies and trials it is important to be able to describe with accuracy the clinical signs and symptoms of HD in order to follow the course of the disease and assess the efficacy of treatments. Likewise, it is important to reduce inter-rater variability to ensure conclusive results. The EHDN working groups have developed three clinical assessment tools so far: the Huntington’s Disease Clinical Characteristics (HDCC), the Quality of Life questionnaire for HD (QoL-HD) and the short version of the Problem Behaviours Assessment (PBA-s) for which training material exist. In addition, the EHDN has developed the certification for the UHDRS^® motor assessment and is currently developing a web-based training and certification platform in collaboration with CHDI, that will contain the HD specific assessments most often used in HD clinical trials. This will make it easier for clinical study staff to ensure that they are properly trained and ready to participate in a wide variety of HD clinical trials at any time.