The determination of energy and digestibility values of new added valueproducts is important for feed formulation. True amino acid digestibility and metabolizable energy of feedstuffs were evaluated in adult meat type crossbred chickens. Sulfur amino acids (cysteine and methionine)and lysine were limiting amino acids in palm kernel meal (solvent extract;PKM) and fermented palm kernel meal (FPKM) with Aspergillus wentiiTISTR 3075. The FPKM with Aspergillus wentii TISTR 3075 lead to an increase in true amino acids digestibility except for arginine. The apparent metabolizable energy (AME; DM basis) of corn, PKM and FPKM were3,628.88, 2,201.83 and 2,080.26 kcal/kg, respectively. The true metabolizable energy (TME) of PKM (DM basis: 2,958.21 kcal/kg) was slightly higher than FPKM (DM basis: 2,843.01 kcal/kg) while the nitrogen corrected apparent metabolizable energy (AMEn), nitrogen-corrected true metabolizable energy (TMEn) of PKM (DM basis: 2,411.84 and 2,603.33 kcal/kg, respectively) were significantly higher than FPKM (DM basis:2,153.11 and 2,333.07 kcal/kg, P = 0.03 and P = 0.02 respectively).Aspergillus wentii may use up nitrogen-free extract (NFE) in PKM as an energy source during the fermenting process, resulting in a lower metabolizable energy of FPKM when compared to PKM (without fermentation). Walailak J Sci & Tech 2009; 6(2): 231-241.