Unlike most neurodegenerative disorders, individuals at risk from Huntington's disease can be identified prior to the onset of clinical signs of the disease by virtue of it being an autosomal dominant condition. This provides the hypothetical opportunity to delay disease onset and/or slow down the progression of the disease in the very early stages ahead of overt features of disease. To help prepare for therapeutic trials of disease-modifying compounds, extensive work has gone into (1) finding ways of better predicting the onset of disease in pre-manifest HD gene carriers (PMGC), (2) defining the extent of non-motor features of HD and (3) identifying robust and reliable tests by which to measure disease progression. In this short review, we summarise some of the major findings in this area of clinical research.