Ginger (Zingiber officinale Roscoe) is a perennial herbaceous plant of the family Zingiberaceae, whose rhizome is generally used as spice, medicine and flavouring agent. The North-Eastern region of India accounts for about 70 % of the total ginger production of the country. The present study was conducted to detect the bioactive chemical compounds present in the rhizomes of three commonly cultivated gingers (Zingiber officinale Roscoe) of Assam locally known as Moran ada, Nadia ada and Jati ada by GC-MS analysis and to estimate and compare the amounts of carbohydrates, starch, protein, flavonoids, total phenolics and ascorbic acid present of the rhizomes of these ginger cultivars. The rhizome of moran ada was found to contain the highest amount of flavonoids and the rhizome of nadia ada was found to contain the highest amount of total phenolic compounds. All the samples of ginger rhizomes were extracted with ethanol and the ethanolic extract was analysed through GC-MS for the identification of different chemical compounds. A total of 30, 27 and 34 chemical compounds were identified in the extracts of rhizomes of jati ada, moran ada and nadia ada respectively. Cis-alpha-bergamotene , 2-methyl-5-((R)-6-methylhept-5-en-2-yl) bicyclo- hex-2-ene, 1,3-cyclohexadiene-5-(1,5-dimethyl-4-hexenyl)-2-methyl, Bicyclo-hept-2-ene-2,6-dimethyl-6(4-methyl-3-pentenyl) and Di-epi-alpha-cedrene were the most abundant compounds identified in the extract of Jati ada; Cis-alpha-bergamotene, 2-methyl-5-((R)-6-methylhept-5-en-2- yl) bicyclo-hex-2-ene, 1,3-cyclohexadiene-5-(1,5-dimethyl-4-hexenyl)-2-methyl, Di-epi-alpha-cedrene, Trans-alpha-bergamotene, 1H-3A,7-methanoazulene,2,3,4,7,8,8a-hexahydro-3,6,8,8-tetramethyl-, and 2-methyl-5-(R)-6methylhept-5-en-2-yl-bicyclo-hexane were the most abundant compounds identified in the extract of moran ada and 2-methyl-5-(R)-6methylhept-5-en-2-yl) bicyclo-hexane, 2-methyl-5-((R)-6-methylhept-5-en-2- yl)bicyclo hex-2-ene, 1,3-cyclohexadiene-5-(1,5-dimethyl-4-hexenyl)-2-methyl, Bicyclo-hept-2-ene-2,6-dimethyl-6(4-methyl-3-pentenyl) and Di-epi-alpha-cedrene were the most abundant compounds identified in the extract of nadia ada.