Twenty buffalo calves of 10-month of age and an average initial live body weight (LBW) 235 kg were chosen and divided into five similar groups (4 animals in each), based on their LBW. Animals were used in 220- days randomized complete block design for feeding trial. This study aimed to evaluate the effect of feeding rations containeddifferent levels from iodine (I)on productive performance of fattening buffalo calves. Concentrate feed mixture (CFM), berseem hay (BH) and rice straw (RS) were given to animals as a control ration (I₀) without supplementation, while the other groups I₁ , I₂, I₃ and I₄, received the control ration supplemented with iodine at the levels of 0.5, 1.00, 1.50  and 2.00 mg I per kg DM intake/h/d, respectively. Five digestibility trials were carried out to determine the digestibility coefficient and nutritive values of experimental rations. Blood samples were collected from all animals at 4 hrs post feeding to measure some blood parameters. Results obtained could be summarized as follows: 1- Supplementing buffaloes ration with different levels of I improved the digestibility coefficient of all nutrients shown the adding 2 mg I was the best. TDN were 62.22, 64.99, 67.68, 69.71 and 72.64% for I₀, I₁, I_2, I₃ and I₄ respectively; the respective values of DCP were 7.01, 7.99, 8.59, 9.25 and 10.00% at the same treatments. 2- Average daily gain were 960, 1045, 1105, 1156 and 1270 gm/h for animals feed I₀, I₁, I_2, I₃ and I₄ respectively, showing the best daily gain with animals feed 2 mg I/kg DMI (I₄). 3- Animals fed ration I₄ were the best feed conversion expressed as kg DM, TDN and DCP per kg gain, being 4.96, 3.61, and 0. 50 kg, respectively. 4- Also, animals fed I₄ appeared to the best economical efficiency (1.91) with the lowest feed cost/kg gain (12.02 LE). 5- Iodine supplementation significant improved the blood contents of RBC, WBC, Hb, PCV, total protein, globulin, glucose, triiodothyronine (T₃) and thyroxin (T₄). Generally, it could be concluded that I supplementation for ration of growing Egyptian buffalo calves considerably improved nutrients digestibilities, nutritive values and economic efficiencies, showing the level with 2 mg I/kg DMI was the best treatment.