Traditional Indian medicinal herbs have been used in the treatment of different diseases in the country for centuries. There have been claims that some traditional healers can successfully treat cancer using herbal drugs. The whole plant of Leucas aspera (Willd.) Link was selected and authenticated for the present study on the basis of ethnobotanical information. The present study concluded that the phytoconstituent was isolated from the whole plant of ethanol extract of Leucas aspera (Willd.) Link and characterized systematically with IR, H1 NMR and mass spectroscopy. The spectral data's of the isolated compound suggested that EELA I showed the structural similarities with Apigenin. Ethanol extract of Leucas aspera (Willd.) Link was screened for in vitro anticancer activities in three different cell lines such as HeLa, Hep G2 and MCF-7 by MTT assay method. HepG2 produced more significant in vitro anticancer activity than other two cell lines. The present study concluded that the antioxidant potentials like flavonoids, saponins present in extract might be responsible for the anticancer activities.