The present study sought to determine the antioxidant activity and protective ability of water-extractable phytochemicals from Salvia officinalis leaves (strongly aromatic leaves used in flavoring cooked foods) on lipid peroxidation induced by some pro-oxidants in rat brain and liver homogenates in vitro. Aqueous extracts of the leaves were prepared, and the ability of the extract to inhibit $25;{mu}M$ $FeSO_4$- and $7;{mu}M$ sodium nitroprusside-induced lipid peroxidation in isolated rat brain and liver was determined. Subsequently, the ascorbic acid content, total phenol content, reducing power, Fe(II) chelating, and ${cdot}OH$ radical scavenging ability of the extracts were determined as indices of antioxidant activity. The results of the study revealed that the extract inhibited malondialdehyde (MDA) production in basal and pro-oxidant-induced lipid peroxidation in the brain and liver in a dose-dependent manner. The percentage induction of lipid peroxidation by Fe(II) and sodium nitroprusside was higher in the brain than the liver; however, the level of inhibition of MDA production in the brain was significantly (P < .05) higher than the liver. The ascorbic acid ($10.3;{pm};;2.5;mg/g$) and total phenol ($7.6;{pm};;1.2;mg/g$) contents the leaves were high; likewise, the aqueous extract had high reducing power and Fe(II) chelating ability but low ${cdot}OH$ radical scavenging ability. This antioxidant and protective effect of this leaf could be harnessed in the management and prevention of degenerative diseases associated with oxidative stress.