Recent advances in molecular genetic and cellular biology have provided new insights into the mechanisms leading to neuronal dysfunction and cell death in the disorders of the cerebellum. Trinucleotide repeat expansions have been identified as an important cause of inherited cerebellar ataxias and mechanisms involved in apoptotic cell death have become centerstage of scientific interest. In the present article, we review the recent findings in trinucleotide repeat disorders and address the possible link of glutamate neurotoxicity, impaired Ca2+ homeostasis and apoptosis.