The pollution caused by fuel combustion either for mechanical or electrical energy generation purposes is nowadays one of the most important environmental issues. It has been proven that combustion emissions, particularly those from cars and trucks, are linked with severe damages to the environment and human health. Along with the environmental problems, is necessary to consider that fossil resources are declining and their exploitation is getting more and more expensive. Bioenergy represent a sustainable solution for energy generation. Bioenergy is renewable energy made from plant-derived organic matter, collectively termed "biomass". Biomass-based energy sources are potentially carbon dioxide neutral and recycle the same carbon atoms. Life cycle assessments are reported to evaluate the net environmental impacts of biofuels. The term biofuel refers to liquid or gaseous fuels for the internal combustion engines that are predominantly produced from biomass. Biofuel policy might capitalize on the production of biofuels supporting rural economic development and sustainable agriculture. Amongst biofuels pure plant oil (PPO) has been investigated. This paper sets out to review the state of the art for PPO use as fuel in diesel engines, based on a wide literature review.