The autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), presenting with spinocerebellar ataxia, dysarthria, nystagmus, and spastic paraparesis, is a gradually progressive hereditary disease. Sensorimotor polyneuropathy may also accompany the symptoms. Herein, we present the electrophysiologic findings of a Turkish family with ARSACS in combination with clinical and genetic features to better describe the characteristics of the polyneuropathy in ARSACS. Regarding the electrophysiologic findings, however, the demyelinating characteristics were prominent and there were findings compatible with secondary axonal degeneration. Rare hereditary diseases such as ARSACS must be suspected in the presence of polyneuropathies with demyelinating characteristics accompanying pyramidal findings and ataxia.