Abstract: Life cycle cost analysis has been carried out to assess the economics of cassava-based fuel ethanol for transport in Thailand. Its relatively high cost over gasoline has put an economic barrier to commercial application. So far, there are different opinions about government support for ethanol in the forms of tax incentives and subsidies. The scope of the study includes the cassava cultivation/processing, the conversion to ethanol, the distribution of the fuel, and all transportation activities taking place within the system boundary. A distance of one kilometer driven by new passenger cars was used as the functional unit (FU) to compare ethanol (in the form of gasohol E10) with gasoline. The results of the analysis show that gasohol has the potential to be competitive with gasoline in terms of cost per FU if cassava farmers can raise their crop yield but lower chemical (fertilizer, herbicide) consumption for crop maintenance. In the industrial phase of the fuel production cycle, utilization of co-products and substitution rice husk for bunker oil as process energy tend to narrow the gap in ex-refinery price between gasohol and gasoline (52% reduction in the price gap). The remaining 38% in the price gap can be eliminated with a strong cut (about 68%) in the profit margin in ethanol conversion phase. Including other difficult-to-quantify benefits of bio-ethanol in a LCC analysis may make the results even more favorable to bio-ethanol.