A study was carried out to look into the effects of dietary zinc and nicotinic acid (niacin) supplementation on growth performance, hematology and biochemical parameters of turkey. The birds were distributed in to four treatments each treatment have three replicates. (3 birds / replicate) T1 no additive as control, fed diets supplemented with Zn (100 mg/kg) T2, Niacin (100 mg/kg diet) T3 and combination of them Zn100 mg/kg+ niacin 100 mg/kg) T4. the results analyzed by CRD arrangement design. Obvious results indicated that supplemented Zn and Niacin enhance the production performance and make a positive effect on the hematology (RBC count, Hb concentration, PCV) and biochemical parameters In each of (AST, ALT, cholesterol and triglyceride