Phenolic and non phenolic derivatives of phenyl styryl ketones were synthesized and evaluated as in vitro inhibitors of iron and cumene hydroperoxide dependent lipid peroxidation in rat brain homogenates. The compounds were also tested for antioxidant activity in phosphatidylcholine liposomes. Phenyl 3, 5-ditert-butyl-4-hydroxystyryl ketone was found to be the most potent inhibitor of peroxidation among all the compounds tested. It was found to be more active than vitamin E. It also reduced the stable free radical l,l-diphenyl-2-picrylhydrazyl to an appreciable extent. © 1995 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.