The present study is based on the regulation of cognitive behaviour and biochemical function in N- Nitrosodiethylamine treated yellow mutant Drosophila melanogaster by snake venom (Naja naja). The flies were grouped into four divisions. (1) Control- Yellow mutant (2) Yellow mutant flies treated with 0.01% NDEA (3) Yellow mutant flies treated with 0.01% NDEA and 0.01% snake venom (4) Yellow mutant flies treated with 0.01% snake venom alone were distributed along with food medium for fourteen days. The behavioural changes were analysed after the experimental period. The behavioural assays including negative geotaxis, smell chemotaxis, phototaxis, taste chemotaxis, hygrotaxis and thermotaxis were performed on yellow mutant and NDEA-treated yellow mutant flies. When compared to the mutant control, the changes of its behaviour were noticed to be diversified in NDEA treated flies but seems to be normal in snake venom administered flies. Snake venom toxins (at appropriate concentrations) are used for the treatment of many pathological conditions. Snake venom has been reported to have anticancer, antioxidant, antihypertensive, antibacterial, anticoagulant and analgesic effects. The levels of non-enzymatic reactions such as thiobarbuturic acid reactive substance (TBARS), protein carbonyl, protein thiol and lipid peroxides were significantly elevated in NDEA treated flies than control yellow mutant flies and correspondingly tend to normalize in snake venom treated groups. Further, superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione peroxidise (GPX) and reduced glutathione (GSH) were decreased in NDEA treated group and were significantly increased in snake venom treated groups. The proteins or peptides and enzymes isolated from snake venom may bind specifically to cancer cell membranes which may affect the migration and proliferation of cells.