Sage (Salvia spp.), belonging to the Lamiaceae family, is an aromatic plant and includes about 900 species that grow in several regions all over the world [1]. This genus showed a very high variability of both morphological and cariological characters [2]. Since ancient times, this genus has been used in folk medicine and as a flavoring agent [3].However, recently many studies have focused on the chemical composition [4], histochemical analysis [5], biological [6], antimicrobial [7], and antioxidant properties [8, 9] of this species. Many papers on the secondary metabolites of S. officinalis can be found in the literature. Recent publications have shown some interesting features of its chemical composition, which is determined by their volatile [10-19] and nonvolatile compounds [20], and their applications in antibacterial [14], antifungal [10], and antioxidant activities [8].In Algeria flora there are 18 species [21]; however, there are no studies on sage oil of these species growing in Algeria. Here we report our findings on the chemical composition of the essential oil of S. officinalis collected from Algiers city of Algeria.Air-dried overground parts of S. officinalis were subjected to hydrodistillation using a Clevenger-type apparatus. A liquid yellow colored oil was obtained with a yield of 0.9% (w/w), based on dry weight of the plants. The oil was analyzed by GC and GC/MS techniques.The chemical compositions of the essential oil of S. officinalis are given in Table 1 in the order of the retention indices, area percentage, and chemical group of the constituents. Forty-eight compounds were characterized in this oil, representing 90.5% of the total oil. The monoterpene fractions (72.2%) were most abundant in this oil and it was particularly rich in oxygenated derivatives (90.7% of this fraction); camphor (20.4%), α-thujone (19.6%), 1,8-cineole (12.3%), and β-thujone (8.0%) were found as the major compounds. In contrast, the sesquiterpene fraction (18.2%) represents a lower percentage in the oil, represented by viridiflorol (8.0%) as the major component. However, twenty components comprised between 0.1-8.0 %, while twenty-three compounds were present in trace amounts (Table 1). The chemical composition of our oil was found to be closely similar to that of the same species collected in Italy [9], Yugoslavia [11], Bulgaria [17], and Iran [19] which were characterized by its large amount of oxygenated fraction.According to previous data of the chemical composition of the oils obtained by hydrodistillation, steam distillation, or ethanol extraction from aerial parts of S. officinalis from different countries [6,8,9,[11][12][13][14][15][16][17][18][19], α-thujone, α-humulene, and camphor have been reported to be the major compounds in these oils (Table 2).Finally, our results are in agreement with samples of Italian [9], French, Romanian, Czech, Portuguese [13], and Turkish [17] sage oils characterized by camphor (22.0-32.9%) as the most important component, in contrast, samples from many countries are represented ...