Six lactating Egyptian buffaloes of 410 ± 16 kg body weight were used in this study. They were fed according to Agriculture and food research council (AFRC) metabolisable energy requirement plus 0, 10 and 15 % of their metabolisable energy requirement as palm oil. It was supplemented to the concentrate mixture to increase the dietary energy density to know if the poor productivity of our buffaloes is due to their gene make up or their requirement of energy is not covered. Milk yield, milk constituents, digestibility and some blood metabolites as affected by palm oil supplementation were studied. A balanced two period's changeover design for several treatments was applied. Results indicated that total dry matter intake was insignificantly increased by 2.80 and 10.97% due to 10 and 15% palm oil supplementation. Total digestible nutrients were significantly (P<0.05) improved by 5.76 and 10.56 % due to palm oil supplementation. Milk yield of 7% fat corrected milk was enhanced significantly (P<0.05) by 27.86 and 52.95 % as buffaloes were fed the energy supplemented rations. The milk fat yield was significantly (P<0.05) increased by 28.72 and 56.14 % due to fat supplementation. At the same trend milk protein yield was increased by 19.65 and 31.44 % due to fat supplementation. The differences were significant (P<0.05). The positive effects of palm oil supplementation on blood glucose, protein and total lipids were studied. The AFRC standards are not sufficient to cover the metabolisable energy requirements for our lactating buffaloes and metabolisable energy supplementation up to 15% is beneficial.