36 Holestien dairy male calves with average body weight of 40.8 ± 3.8 kg were assigned to a completely randomized design from days 4 after birth to two weeks post weaning, to investigate the effect of garlic extract and monensin on performance ( DMI, ADG, age and weight of weaning, feed convertion ratio, withers height, appearance digestibility of dry matter, CP, NDF and ADF), fecal score, serum cholesterol and serum albumin: globulin ratio. Treatments were included: 1- Control (non additive), 2- Monensin (40 mg per kg of starter dry matter), 3- 1gram, 4- 1.5gram, 5- 2gram and 6- 3 gram garlic extract per day for each calf. Dry matter intake in week three was higher in treatment 5 compared to 2 and 3 treatments. Dry matter intake in week four was higher in treatment 5 compared to 3 and 4 treatments and dry matter intake in week five was highest in treatment 5. In the pre weaning period, DMI was higher in treatment 5 compared to monensin supplemented treatment (p 0.05). Average daily gain in week three was similar in all treatments. Average daily gain in week four was higher in treatment 5 compared to treatment 4 and average daily gain in week five was highest in treatment 5. Befor weaning, ADG was highest in treatment 5 and was higher in treatments 3 and 4 compared to control (p 0.05). Feed convertion ratio in week 3 was highest in treatment 3. Feed convertion ratio in week four was higher in treatment 6 compared to treatment 3. Feed convertion ratio in week five was higher in treatment control compared to treatments 3 and 6. In the pre weaning period, feed convertion ratio was highest in treatment 5 and was higher in treatments 2, 3 and 4 compared to control (p 0.05). Days of weaning was lower in treatment 5 (34 days) compared to control (43 days) how over weaning weight was highest in treatment 5 (71.2 kg). Fecal score was not affected by any dietary treatments. Digestibility of dry matter and NDF decreased in treatment 2 compared to control but digestibility of CP and ADF were not affected by dietary treatments. After weaning, DMI, ADG and feed convertion ratio were not affected by any treatments. Digestibility of CP was lower in treatment 3 in comparsion to control, while appearance digestibility of dry matter, NDF and ADF were not affected by any treatments. Compairing to control, serum cholesterol was lower for treatments 3, 4, 5 and 6 (p 0.05) and serum albumin: globulin ratio was similar in all treatments. Key Word Dairy calves, Monensin, Garlic extract, Garlic powder, Performance, Health.