Background: To determine the effect of essential oil obtained from a traditionally used medicinal plant Tridax procumbens L, on lung metastasis developed by B16F-10 melanoma cells in C57BL/6 mice. Materials and Methods: Parameters studied were toxicity, lung tumor nodule count, histopathological features, tumor directed capillary vessel formation, apoptosis and expression levels of $P^{53}$ and caspase-3 proteins. Results: In vitro the MTT assay showed cytotoxicity was found to be high as 70.2% of cancer cell death within 24hrs for $50{mu}g$. In vivo oil treatment significantly inhibited tumor nodule formation by 71.7% when compared with untreated mice. Formation of tumor directed new blood vessels was also found to be inhibited to about 39.5%. TUNEL assays also demonstrated a significant increase in the number of apoptotic positive cells after the treatment. $P^{53}$ and caspase-3 expression was also found to be greater in the essential oil treated group than the normal and cancer group. Conclusions: The present investigation showed significant effects of the essential oil of Tridax procumbens L in preventing lung metastasis by B16F-10 cell line in C57BL/6 mice. Its specific preventive effect on tumor directed angiogenesis and inducing effect on apoptosis warrant further studies at the molecular level to validate the significance of Tridax procumbens L for anticancer therapy.