Taxol is a novel and promising oncolytic agent the use of which is hampered by its neurotoxicity. We now describe a taxol-induced neuropathy in rats and its prevention by the adrenocorticotropic hormone-(4-9) (ACTH-(4-9)) analog, ORG 2766. A decrease in sensory nerve conduction velocity was seen in taxol-treated rats, both with daily injections of small amounts (6 mg/kg per week) and with weekly injections of higher amounts (9 mg/kg per week) of taxol. Concomitant administration of ORG 2766 completely prevented the occurrence of a neuropathy.