Huntington's disease (HD) is a chronic neurodegenerative disorder, characterized by the following triad of clinical hallmarks: chorea, cognitive impairment and behavior disorders [8]. In 1993 the gene responsible for HD, whose mutation results in HD, was identified and mapped on the chromosome 4p16.3 [6]. The mutation is a characteristic expansion of a CAG nucleotide triplet. In this paper we present a 36-years-old female patient with HD who was submitted to a complete diagnostic procedure including genetic testing. Her pedigree was reconstructed using available medical documentation and tracing other members of her family.