Background Fluoride may induce oxidative stress and apoptosis. It may also lead to neurobehavioural defects including neuromuscular damage. The present study aimed to explore the effects of sub lethal concentrations of sodium fluoride (NaF) on the lifespan and climbing ability of Drosophila melanogaster. In total, 0.6 mg/L and 0.8 mg/L of NaF were selected as sublethal concentrations of NaF for the study. Lifespan was measured and climbing activity assay was performed. Results The study showed significant decrease in lifespan of flies treated with fluoride. With increasing age, significant reduction in climbing activity was observed in flies treated with sodium fluoride as compared to normal (control) flies. Flies treated with tulsi (Ocimum sanctum) and NaF showed increase in lifespan and climbing activity as compared to those treated with NaF only. Lipid peroxidation assay showed significant increase in malondialdehyde (MDA) values in the flies treated with NaF as compared to control. The MDA values decreased significantly in flies treated with tulsi mixed with NaF. Conclusions The results indicate that exposure to sub lethal concentration of NaF may cause oxidative stress and affect the lifespan and climbing activity of D. melanogaster. Tulsi extract may help in reducing the impact of oxidative stress and toxicity caused by NaF.