A man who worked as an operator in a factory of sterilization of heat-sen-sitive materials has been exposed to ethylene oxide for seven years. He developed a mild sensori-motor polyneuropathy. The electromyography and nerve conduction studies showed an axonal degenerative type of neuropathy. The sural nerve biopsy revealed mild loss of myelinated fibers, some fibers with axonial degeneration, some clusters of regeneration and few rows of myelin ovoids in the teased nerve fiber preparation. This is the first report of ethylene-oxide polyneuropathy in Brazil.