Abstract Volatile compounds from leaves of Ocimum gratissimum L. (two chemotypes) and O. minimum L. were isolated by hydrodistillation and analyzed by GC and GC/MS. Twenty 35 and 31 constituents were identified, respectively, for O. gratissimum (var. I and II) and O. minimum, of which eugenol (75.5%) and germacrene D (6.2%), p-cymene (33.3%), thymol (31.3%) and methyl chavicol (36.3%) and linalool (17.8%) were the most abundant, respectively. The oils of O. gratissimum present a significant radical scavenging activity whereas O. minimum oil was found to be much less efficient. Key Word Index: Ocimum gratissimum Ocimum minimum Labiataeessential oil compositioneugenolmethyl chavicolp-cymenethymollinaloolradical scavenging activity