The effects of neurotoxic solvents, i.e. 2,5-hexanedione (2,5-HD), 2,5-hexanediol (2,5-HDiol) and the non-neurotoxic solvent, 2,4-hexanedione (2,4-HD) (500 mg/kg body wt./day, i.p.), have been studied on the lipid composition of brain and sciatic nerves in weanling rats. Five-day-old rats were administered a solvent daily for 21 days. Clinical signs of peripheral neuropathy appeared in 2,5-HD and 2,5-HDiol treated groups. Absolute weights of brain, spleen, thymus significantly decreased with 2,5-HD. Cholesterol content in whole brain homogenates and myelin was significantly reduced with 2,5-HD and 2,5-HDiol treatment. There was also a significant reduction in ubiquinone content of brain with 2,5-HD and 2,5-HDiol treatment. On exposure to neurotoxic chemicals to weanling rats, significant alteration in lipid profile was observed in the brain, which may be one of the key factors in the development of neuropathy.