Limnophila rugosa (Roth.) Merr. is an important Indian traditional medicinal plant, used for the treatment of various diseases. Fragrant volatile oils isolated from the aerial parts of L. rugosa collected from two diverse localities in northern India (foothills and mid-hills) were investigated by gas chromatography (GC) and GCâmass spectrometry (GCâMS). The essential oil yields and chemical compositions of L. rugosa from the two localities differed significantly. The population collected from the mid-hills was rich in essential oil (0.44%) compared with the population from the foothills (0.25%). The essential oil of the foothill population was characterized by the dominance of methyl chavicol (76.6%), followed by (E)-anethole (19.1%). Conversely, the essential oil of the mid-hill population was dominated exclusively by (E)-anethole (88.5%). These genetic resources of L. rugosa can be utilized as a valuable source of the high-value aromachemicals, namely methyl chavicol and (E)-anethole.