AbstractPhenylpropenes play an important role in plant defense against animals and microorganisms, and in attracting pollinators and insects. We report the genetic inheritance of methyl chavicol and eugenol following a cross between the sweet basil varieties ‘Perrie’ and ‘Cardinal,’ eugenol and methyl chavicol chemotypes, respectively. Methyl chavicol was detected only in ‘Cardinal,’ accounting for more than 95% of the total phenylpropenes. Eugenol was most abundant in ‘Perrie,’ accounting for more than 99% of the total phenylpropenes. Eugenol, chavicol and methyl chavicol were detected in F1 hybrids at intermediate levels (10%–52%) without statistical differences (p > .05) for any compound among the F1 progeny arising from the different crossed pairs. The F2 progeny segregated into three groups, 23%–25% to a eugenol chemotype, 23%–25% to a methyl chavicol chemotype, and the remaining (~50%) into an intermediate mixture of the two compounds. This distribution fitted a segregation ratio of 1:2:1 (χ2 = 1.71; p = .4249), suggesting that the phenylpropene phenotype is regulated by a single bi‐allelic gene with incomplete dominance. A putative association with biosynthesis enzymes is discussed.