Abstract: The chemo preventive efficacy of Lycopene and D-arginine with regard to lung carcinogenesis was investigated using benzo (a) pyrene induced swiss albino mice a lung cancer model. A number of natural and synthetic antioxidants are known to retard chemical carcinogenesis in experimental animal model. Here lycopene is a pure antioxidant constituent of tomato and D-arginine complex amino acid having anticancer and antiproliferative effect which inhibits tumour growth was found to suppress benzo(a) pyrene induced lung cancer in Swiss albino mice as revealed by the increase in activity of enzymic antioxidant (Superoxide dismutase, Catalase and Gluthathione peroxidase) and nonenzymic antioxidant (reduced glutathione, vitamine E and vitamine C) levels when compared to lung cancer bearing animals. Values in animals treated with lycopene 10 mg kg-1 body weight concomitant with D-arginine 500 mg kg-1 body weight shows the reversal to near normal. Further confirmed by increase in the tumor marker enzymes (Aryl hydrocarbon hydroxylase, γ-glutamyl transpeptidase, 5’-Nucleotidase, lactate dehydrogenase and Adenosine deaminase). The above studies also confirm the induction of lung cancer in Benzo (a) pyrene administered mice. Post oral treated with Lycopene and D-arginine for 10 weeks prevents the alterations and restores the enzymes activated to near normal. These findings through overall data demonstrate that the animals post treated with Lycopene and D-arginine may prevent lung cancer and hence will aid in establishing the chemopreventive effect on combinations when administered orally on lung cancer bearing animals.