In this paper, the methodology of life-cycle assessment was applied to an ethanol production process based on catalytic reaction. The environmental performance of the process was quantified and compared with that of the fermentation process. The purpose of the assessment was to develop design guidelines for the environmentally better ethanol production. The assessment was carried only on the stages of raw material acquisition through ethanol manufacture since it was assumed that ethanol from two processes had the same environmental impacts through its use and discard. The inventory analysis of the catalytic process resulted in that carbon dioxide from methanol production was the major environmental impact. The impact assessment showed that the fermentation process was environmentally better than the catalytic one. Suggestions for environmental improvement of the catalytic process were prepared based on the assessment results.