There are many different causes of anhidrosis. Sweat glands can be absent, atrophic or blocked; sympathetic innervation may be disturbed, or central nervous system damage may prevent perspiration. We present a patient with multiple system atrophy ( MSA) who presented with unilateral anhidrosis of the trunk. MSA is a sporadic neurodegenerative disorder of adults involving the pyramidal, extrapyramidal, cerebellar and/or autonomic system. The findings in our patient could be explained by a depletion of catecholaminergic sympathetic neurons of the thoracic spinal neurons.