Salvia officinalis L. is an aromatic herb that is widespread in the Tiaret region of Algeria where it plays a major role in the translational pharmacopoeia. This work aims at phytochemical screening, studying of acute toxicity and evaluation of antidiabetic activity of ethanolic extract of S. officinalis in Wistar rat induced by a diabetogen "Alloxan". First, the phytochemical characterization was carried out by determination of the main bioactive compounds. It was followed by studying of acute toxicity in Wistar rat. Then, the evaluation of antidiabetic activity was performed by induction of diabetes in Wistar rat with Alloxan. The results showed the richness of the ethanol extract of S. officinalis in different bioactive compounds such as tannins, flavonoids, cardiac glycosides and alkaloids. The absence of serious clinical signs or dead rats during the observation period indicates that the ethanol extract of S. officinalis administered per os is devoid of acute toxicity in rats at 2000 mg kg-1 body weight. For the antidiabetic activity, results reported a highly significant reduction in blood glucose, cholesterol levels at a dose of 300 mg kg-1 in diabetic rats.