In the present study the olfactory system of hereditary ataxia patients was tested using the smell identification test. Two previous findings suggested a possible olfactory impairment in these patients. First, an olfactory dysfunction has been found in different neurodegenerative diseases, and second, human functional imaging has shown cerebellar activation during olfaction. As an initial approach to determine if cerebellar ataxia impairs the olfactory process, cerebellar ataxia patients, along with basal ganglia patients, were tested. The results show an olfactory deficit in both basal ganglia and hereditary ataxia patients. Further exploration of the olfactory capacities in hereditary ataxia is necessary to elucidate the specific nature of the deficits.