Ocimum species are largely used in Brazil both as a condiment and in traditional medicine against bronchitis, cough, and sorethroat in the form of tea or syrup. As little research has examined the natural products from Brazilian basil, 14 accessions of Ocimum, including O. basilicum (4), O. campechianum (3), O. gratissimum (6), and O. kilimandsharicum (1), collected in Brazil were grown in the Purdue Univ. greenhouse and upon maturity harvested, the volatile oil extracted and analyzed by GC/MS. Thirty-one constituents were identified. Three accessions of O. gratissimum showed high content of eugenol (40% to 66%), while the other accessions contained either high thymol (33%) or p-cymene (28% to 42%). The constituents of the single O. kilimandscharicum included 1,8-cineole (39%), methyl-chavicol (21%), and ß-bisabolene (23%). O. campechianum accessions contained either high 1,8-cineole (62%) or high ß-caryophyllene (79%). O. basilicum could also be separated chemically: a linalool:methyl chavicol type (47:28%); one methyl chavicol type (72%), and a third, methyl cinnamate (61%). One accession was identified containing >90% trans-methyl cinnamate, which crystallized during extraction. Plants rich in targeted compounds, such as the one with 90% trans-methyl cinnamate, can be used as source of germplasm for breeding and potential commercialization