Huntington's disease (HD) is the most common inherited neurodegenerative disease and is characterized by uncontrolled excessive motor movements and cognitive and emotional deficits. The mutation responsible for HD leads to an abnormally long polyglutamine (polyQ) expansion in the huntingtin (Htt) protein, which confers one or more toxic functions to mutant Htt leading to neurodegeneration. The polyQ expansion makes Htt prone to aggregate and accumulate, and manipulations that mitigate protein misfolding or facilitate the clearance of misfolded proteins tend to slow disease progression in HD models. This article will focus on HD and the evidence that it is a conformational disease.