The aim of the present study was to investigate the effect of dietary supplementation with Herbal oil mixture (HEOM) on growth performance, body composition, some blood parameters and intestine histology of Nile tilapia fish fingerlings. One hundred and Eighty Nile Tilapia (Oreochromios Niloticus) fish fingerlings were randomly divided into three treatment groups of 60 fish each (negative control and Herbal oil mixture (HEOM) at two levels). Each treatment group was further sub-divided into three replicates of 20 fish per replicate. The groups fed the diet as the following, group I fed basal diet (control). Group II fed basal diet + 0.05% HEOM.  Group III fed basal diet + 0.1% HEOM for 12 weeks. The obtained results confirmed the significant gradually (with increasing the feed additive level) showed improvements in fish final weight, weight gain, specific growth rates, feed utilization (feed intake and feed conversion) by increasing herbal oil mixture levels. These feed additives, also, significantly improved fish carcass composition (protein, ether extract, energy content) Total and differential leukocytic count was improved.  Herbal oil mixture reduced blood Cholesterol, triglycerides, glucose and liver enzymes. These additives improved intestine histology. So, it could be recommended the addition of 0.1% herbal oil mixture to Nile tilapia fish diet.