Fleshing scrap is a kind of wastes produced during leather making process and used in the test of manufacturing biodiesel. The early step of manufacturing biodiesel is fat recovery from fleshing scrap. Hence, we investigated the influence of the way of fat recovery on the fatty acid composition. We used three different recovery ways, that is chemical method by protein decomposition with acid/fat recovering, physical method by protein denaturalization with heat and vacuum/fat pressing, and biodiesel method by protein decomposition/fat recovering. The biological method yielded the best results in terms of appearance transparency. It was most effective to lower acid value. Also the recovered fat by biological method would be favorable methyl-ester reaction raw material for biodiesel because it contains more than 5% of oleic acid among unsaturated fatty acid.