This experiment was conducted in Inshas Poultry Research Station, Ministry of Agricultural, Egypt, A total number of 420 hens and 105 cocks from Silver Montazah chickens (SM) (Egyptian local strain) flock were used to investigate the effect of dietary supplemental of arginine (Arg) levels on plasma nitric oxide (NO) and Insulin-like growth factor (IGF-I), testosterone (Testo) and luteinizing (LH) hormones concentrations, and their relation to productive and reproductive performance during laying period (28-40 wks of age). Birds were randomly divided into 7 experimental groups (each of 3 replicates). Each replicates consisted of 20 hens and 5 cocks. The 1st group (T1) was fed the basal diet and served as the control group with no additional Arg (15, 12.5 and 12.8 g Ar /kg diet) for the starter, grower and finisher diet, respectively. The 2nd, 3rd and 4th groups were fed the basal diet supplemented with 2, 2.5 and 3 g Arg/kg diet, respectively, from one-day old to 40 wks of age (17, 17.5 and 18 g Arg /kg diet) for the starter, (14.5, 15 and 15.5 g Arg /kg diet) for the grower and (14.8, 15.3 and 15.8 g Arg /kg diet) for the finisher diet was used. However, the 5th, 6th and 7th groups were fed the basal diet (15 g and12.5 Arg/kg diet) for the starter, grower diet and the basal diet supplemented with 2, 2.5 and 3 g Arg/kg diet (14.8, 15.3 and 15.8 g Arg/kg diet) for the finisher diets, respectively, only from 28 to 40 wks of age. Results indicated that hens fed Arg supplementation significantly improved feed conversion ratio (FCR) for all treatments except T2 and T3 groups in compared with control group. Egg production, egg mass and total leucocytes count was higher in treated hens from 28 to 40 wks of age than in control ones. Most semen quality parameters, fertility, hatchability and lymphocyte (L) ratio were improved by dietary treatments. However, hetrophils (H) and H/L ratio were decreased by Arg supplementation. Significant increase (P≤0.05) appear in NO trait, IGF-I, LH and Testo hormones concentrations for hens in T6 and T7 from 28 to 40 wks of age in compared with treated hens from one-day old to 40 wks of age (T2, T3 and T4) and the control group. While, there were no significant differences in live body weight, feed consumption, egg weight and egg quality traits among all treatments in compared with control group at 40 wks of age. It could be concluded that dietary Arg supplementation to SM hens from 28 to 40 might improve the egg production, reproductive performance and some semen quality parameters. Also, it might have a mediated effects on NO, IGF-I, LH and testosterone hormones levels.