In this case study, we describe the symptoms, neurological exam, neuropsychological test results, and brain pathology of a man who died with Huntington's disease (HD). HD is a rare neurodegenerative disease. Like other movement disorders involving the basal ganglia, HD affects motor, cognitive, and psychiatric functioning. The disease follows an autosomal dominant pattern of inheritance, with onset of symptoms most commonly occurring in the late 30s or early 40s, as in this patient. HD is caused by an unstable expansion of the trinucleotide CAG, coding for glutamine, on chromosome 4. Despite knowledge of the gene mutation responsible for HD, no definitive treatment is currently available to slow or halt progression of the disease. However, symptomatic treatment can significantly improve the quality of life for patients with HD.