Plants are the fashionable foundation of drugs for the mainstream of the world people. The present study was carried out to investigate the constituents of leaves of two major commercial varities of sweet and bitter orange Citrus aurantium L and Citrus sinensis L. Alkaloids, flavonoids, steroidal glycosides, volatile oils, terpenoids, and sterols were confirmed by preliminary phytochemical studies. The physicochemical parameters like Loss on drying, Extractive values, and Ash values were also evaluated. GC-MS analysis of essential oils of Citrus aurantium L. contains 25 compounds and Citrus sinensis L. showed the presence of 30 bio-active compounds. The major components of Citrus aurantium are 1,3-Cyclohexadiene, trans-3-Caren-2-ol, Eucalyptol, γ-Terpinene, Linalool, 2-Cyclohexen-1-ol, 6-Octenal, Terpinen-4-ol, Benzene, α-Terpinyl acetate, 2,6-Octadien-1-ol, Cyclohexane, Caryophyllene, Tetra methyl bicyclo undeca-2,6-diene, 4-Isopropyl-3,7-dimethyloctahydro-1H-cyclopentane, Naphthalene, Caryophyllene oxide, 1-Naphthalenol, Cardinol, and Phytol. Whereas Citrus sinensis L essential oil shows the presence of Eucalyptol, α-Phellandrene, D-Limonene, 3-Carene, Eucalyptol, β-Ocimene, γ-Terpinene, Linalool, Isoneral, Terpinen-4-ol, 6-Octenal, 3,7-dimethyl, α-Terpineol, Citronellol, 2,6-Octadien-1-ol, Neral, Geraniol, trans-Geranic acid methyl ester, 6-Octen-1-ol, 2,6-Octadien-1-ol, 3,7-dimethyl acetate, 3,7-dimethyl-acetate, Geranyl acetate, Caryophyllene, Humulene, Caryophyllene oxide, and Phytol as the notable compounds. However, both species show similar compounds in their GC-MS analysis with little difference. This study will help us to know the similarities and differences between the closely related medicinally important species of C.sinensis and C.aurantium on their phytochemical nature. © 2023 Elsevier B.V., All rights reserved.