This experiment aimed to study effects of metabolizable energy and protein levels on the productive and reproductive performance of Sinai laying hens from 24 to 40 wk. A total of 180 Sinai laying hens was randomly assigned to six experimental diets of 2,850 (H ME = high ME), or 2,700 = low ME) kcal of ME/kg, each containing CP levels of 18% (H CP = high CP), 16% (M CP = medium CP), or 14% (L CP = low CP) in a 2× 3 factorial arrangement of treatments. Each dietary treatment contained 30 single-caged birds. The results were obtained as follows: final body weight (FBW), change in body weight (CBW), daily protein intake, daily energy intake, protein efficiency ratio (PER), energy efficiency ratio (EER), feed conversion ratio (FCR), egg number (EN), egg weight (EW), daily egg mass (EM), hen-day egg production rate (HDEP), were significantly improved in birds fed the high-energy-diets (P<0.01) compared with those fed the low-energy-diets. However, birds fed the low-ME diets consumed more feed compared with fed on high-energy-diets. Birds fed the diets termed as (H CP or M CP ) displayed significantly higher (P≤0.01) final body weight (FBW) and change in body weight, egg number and hen-day egg production rate than those received the low-CP diet (P<0.01). Increasing dietary protein level led to a gradual improvement in FBW (g), CBW, daily protein intake, EER, FCR, egg number, egg weight, daily egg mass and hen-day egg production rate. Interactions between ME and CP levels in the previously mentioned criteria were significant (P<0.05). Plasma cholesterol was significantly increased as a result of feeding on the high-ME diets compared with those given the low-ME diets. The same trend was also observed in respect of protein levels where there were significant differences on plasma activity of ALT which significantly increased (P≤0.01) when hens were fed on the high-CP diets compared with those fed on the diets containing L CP and M CP . Plasma cholesterol was significantly increased (P≤0.01) by increasing ME level in the diet with any dietary protein level compared with other treatment groups.The present results revealed that the diets containing ME level of 2,850 kcal/kg with 18 or 16% protein can improve egg production characteristics of Sinai laying hens. From the economic view point it can be suggested that a diet containing 16% protein with 2850 kcal/kg is optimal for Sinai laying hens to achieve the highest profitability compared with other treatments during studied period from 28-40 weeks of age.