Four hydroxyethyl rutosides, 7,3',4'-trihydroxyethyl quercetin, quercetin and a commercial standardized mixture of hydroxyethyl rutosides were investigated on non-enzymatic lipid peroxidation, for hydroxyl radical scavenging activity and interaction with 1,1-diphenyl-2-picrylhydrazyl stable free radical (DPPH). It was found that the tested compounds exhibited a considerable inhibition of microsomal lipid peroxidation. They were less active than the reference compound quercetin, and this was attributed to their structural characteristics. They were also found to be potent hydroxyl radical scavengers and to interact with DPPH. As hydroxyl radical scavengers, they were more potent than the scavengers mannitol and dimethyl sulphoxide. These properties could be considered as a useful and exploitable combination.