Coal, petroleum and natural gas are the main sources of energy in the world today. All three sources are fossil-derived, non renewable and cause global warming by emitting greenhouse gases. Various crops like maize, rapeseed/canola, soybean, sugarcane, palm oil, jatropha and sunflower are being cultivated to produce bio-fuel. But crop bio-fuel has high cost of production; needs large amounts of fresh water for irrigation, which eventually will lead to global food shortage. There is need to find non-agricultural crops that grow in the wild, for bio-fuel production. Colocynth is one of the best candidates for this purpose as it has the potential to yield high oil seed production, while growing on marginal lands. The plant grows well in sandy soils, hot climate with little moisture and does not need much care. Since the colocynth seed has high oil contents of 22-53 %, it may produce more than 3,000 kg/ha of oil, which is comparable to major oilseed crops. Consequently, this hardy vine can be used to generate large scale vegetable oil for a viable bio-fuel industry.