This experiment was carried out to determine the effect of adding 0, 0.25, 0.50, 0.75, and 1% of dry thyme (Thymus vulgaris) and sage (Salvia officinalis) leaves to the ration of Nile tilapia (Oreochromis niloticus) on growth performance, feed and nutrient utilization, whole body composition, hematogram, protein profile and the activity of serum enzymes. Fingerlings of 15g average weight were stocked in 27 glass aquaria (105x32x40cm) at a rate of 15 fish in each. Fish in each aquarium were handly fed on the experimental pelleted feeds twice daily, six days a week at a rate of 3% of body weight daily for a period of 105 days. The results showed that, nutrient utilization, growth performance, hematogram, protein profile and activity of serum enzymes were improved with adding the thyme at level of 0.25 and 0.5% and sage at 0.5% and 0.75%. Also, fish fed rations containing 0.25,0.5, 0.75. and1% thyme or 0.75, and 1% sage had significantly (P<0.05) lower body fat, ash and energy contents but significantly (P<0.05) higher dry matter and body protein content.There were no significant mortalities among fish groups during the experimental period. Therefore, the levels of 0.25 or 0.5% thyme and 0.25, 0.5 or 0.75% sage are recommended as growth promoters for Nile tilapia due to their favorable effects on growth performance and health status.