The present work was aimed to study chemical diversity among Ocimum species collected from Eastern Coastal Plains of India. Seventeen accessions representing five Ocimum species namely; O. basilicum L., O. tenuiflorum, O. gratissimum L., O. americanum L. and O. citriodorum Vis. were investigated for essential oil content and oil composition by GC/FID and GC/MS. Essential oil content isolated from aerial parts of Ocimum species varied from 0.27% to 0.47% on fresh weight basis. A total of eighty-three compounds, constituting 95.2â99.9% of total oil were identified in five Ocimum species. Major volatile constituents identified were monoterpenoids (camphor, linalool, neral, nerol, geraniol, 1,8-cineole, ocimenes) and phenylpropanoids (methyl chavicol, eugenol, methyl eugenol, methyl cinnamate). Ocimum species germplasm was classified into different chemotypes. O. americanum accessions belonged to camphor-rich chemotype (38.7â51.4%); while O. gratissimum belonged to eugenol-rich chemotype (59.7â71.8%). A unique high (E)-methyl cinnamate-rich chemotype (61.3â69.0%) was identified in O. basilicum whereas eugenol and methyl eugenol-rich two chemotypes were identified in O. tenuiflorum germplasm. Essential oil profiling of O. citriodorum showed two distinct chemotypes rich in geranial/neral and methyl chavicol.