The present study was performed to investigate the effects of dietary supplementation of chromium-methionine (Cr-Met) and/ or vitamin C (Vit C) on performance, blood parameters, egg quality and stress status of laying hens subjected to high stocking density. A total of 360 Hy-line W-36 leghorn hens of 28 wk-old were used in a 3×2×2 factorial arrangement including 3 levels of Cr (0, 500 and 1000 as Cr-Met), 2 Vit C levels (0 and 500 ppm) and 2 cage densities (5 and 7 hens per cage). After a 10 d adaptation period, the main recording period was started for 70 days. Dietary Cr-Met supplementation caused significant improvements in egg production rate, egg mass as well as feed consumption. In addition, Cr-Met decreased (P 0.01) feed conversion ratio at the first 35 d and tended to decrease this parameter in the whole trial period. Similarly, addition of Vit C numerically increased egg production and egg mass in the whole experimental period. Egg production, feed intake and feed conversion ratio in the whole period was affected by Cr-Met by Vit C interaction so that, co-utilization of two supplements had the better effects only at the levels of 500 ppm Vit C and 500 chromium. Cage density had significant effects on egg production rate, egg mass and feed consumption so that, density of 7-hens/cage significantly decreased the mentioned parameters; however, cage density had no considerable effect on feed efficiency. Interestingly, dietary Cr-Met caused significant (P 0.05) improvements in yolk color index, shell breaking strength and Hough unit at mid-period. Only significant effect of Vit C in the light of egg quality parameters was observed for yolk color index at the mid trial period. On the other hand, the marked negative interacted effects (P 0.05) between Cr-Met and Vit C was seen for shell thickness and shell breaking strength at the end period. Cage density of 7 hens/cage improved egg shell thickness. Cr-Met supplementation of diets decreased yolk triglycerides (P 0.05), and serum insulin (P 0.0001) and glucose (P 0.01), but had no clear effect on yolk cholesterol. Serum insulin and glucose of hens that kept at 7 hens/cage density were significantly (P 0.001) increased. Dietary inclusion of Cr-Met resulted in numerical increase in serum HDL concentration. Also, Cr-Met increased Newcastle antibody titer at d 14 post vaccine inoculation and tended to improve it at 7 th post vaccination. In contrast, density of 7 hens/cage significantly (P 0.01) decreased the Newcastle antibody titers. Totally, it seems that the organic Cr-Met supplement can improve laying hen's performance probably with decreasing the stressful conditions, and in this regard, synergistic effects among Cr-Met and Vit C can be considerable