We examined cognitive and psychiatric disturbances in patients with Huntington's disease (HD) in comparison to at-risk asymptomatic subjects. Cognitive and psychiatric scales and an HD motor scale were administered to 40 HD patients, 17 pre-symptomatic HD gene carriers (AR+) and 28 non gene carriers (AR-). HD patients did worse than AR+ and AR- in all motor, cognitive and psychiatric measures, while AR+ and AR-subjects did not differ between each other. HD patients had high scores for negative psychiatric symptoms, but there was no correlation between illness duration and psychiatric or cognitive performance. In HD, disease course and symptomatology are heterogeneous and negative psychiatric symptoms are common.