The purpose of this research was to perform a preliminary inventory of the waste fat generated from beef cattle and fowl in Mexico that could be used for biodiesel production. Additionally, the CO 2 emissions reduction that could be achieved by using the potential biodiesel to replace an energy-equivalent amount of fossil diesel was assessed. Based on national reports for the year 2014, it was estimated that the non-edible fat from beef cattle and fowl annually generated in Mexico is sufficient to produce 216.0 kt of biodiesel, which would furnish 8379 TJ. This amount is equivalent to 1.5% of the energy annually consumed in Mexico as fossil diesel for road transport. The potential 216.0 kt of animal fat-based biodiesel that can be produced annually could replace 198.3 kt of fossil diesel and thus allow a reduction in the WTW (well to wheels) emissions of 592.3 kt CO 2 , which represents 1.5% of the WTW CO2 emitted from the combustion of the fossil diesel used for road transportation in Mexico in the year 2014.