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 CO2 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 CO2, 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. (C) 2016 Society of Chemical Industry