Taiwan is a high energy-importing nation with more than 98% of our energy supplied by imported fuels in 2004. The diversification of kinds and sources of primary fuel is becoming vital energy issues in the country. In this regard, biomass energy like biodiesel fuel from waste edible oil is thus becoming attractive due to the environmental and energy policies for promoting sustainable development and environmental pollution mitigation in Taiwan. The objective of this paper is to present an analysis of energy utilization from waste edible oil for the diesel production in Taiwan. The description in the paper is thus summarized on current status of diesel fuel and edible oil supply and consumption, and waste edible oils, and then centered on new/revised promotion legislation/regulations especially concerning the waste-to-biodiesel in the measures of environmental protection and economic/financial incentives. Finally, we survey the first demonstration plant in the production of biodiesel from waste edible oil including process description and benefit analysis, which has started to be operated in October 2004 on an industrial scale of 3000 metric tons per year.