This study was carried out to evaluate the effects of dietary saponin supplementation and essential oil (thymol and carvacrol) on growth performance and some biochemical parameters of broiler chickens. Two hundred and fourty one-day-old chicks (Ross 308), which was randomly divided into 8 treatment groups each with three replicates of 10 birds. The first treatment (T1) was fed a diet without saponin while, saponin 10 ppm (T2), 20 ppm (T3) and 40 ppm (T4), however birds in group 5 (T5) fed diet without saponin and in drink water with 50 ppm essential oil, saponin 10 % with 50 ppm EO (T6), 20 ppm with 50 EO (T7) and 40 ppm with 50 EO (T8). Results obtained revealed that chicks fed basal diet with saponin had significantly (P < 0.05) better body weight, weight gain and feed conversion ratio, while feed intake was reduced comparison with control treatment. Chicks that received a diet supplemented with saponin at 20 or 40 ppm with 50 ppm EO significantly (P<0.05) improved growth performance compared with the other treatments. Supplementation of essential oils and saponin at levels of 40 and 20 ppm, respectively significantly increased Serum protein fractions (total protein, albumin and globulin). Significant reductions in serum total cholesterol and triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol were detected in the group that fed diet with 20 and 40 ppm diet saponin plus EO 50 ppm compared with other diets. Consequently, these findings suggest that phytogenic feed additives, particularly essential oils combined with saponin, hold promise as effective agents for enhancing the growth performance of broiler chickens