This study was undertaken to investigate stocking density (SD) and nutrient density (ND) effects on productive performance, egg quality, carcass characteristics, and blood biochemical parameters of Japanese quails. Two hundred eighty-eight quails 3×2 factorial arrangement was used with three stocking densities and two dietary nutritional densities and kept at three rates of cage SD (277.8, 208.3 and 166.7 cm²/bird). Three of these groups were fed on a normal nutrient-density diet and the second three groups were fed on a high nutrient-density diet (105% of the recommended nutrient requirements for laying quails) and managed similarly from 7 to 19 weeks of age. Carcass characteristics and most blood parameters, certain criteria of productive performance of quails were not affected by SD and ND. Increasing SD impaired egg production rate (EPR), daily feed intake (DEI), and daily egg mass (DEM) of quails. However, increasing ND improved EPR, DFI and DEM but had no effect on all criteria of egg quality. Most egg quality traits were not affected by SD, while yolk index (YI) deteriorated and ST improved with increasing SD. There were inconsistent differences in serum levels of MDA and COR, but P level increased due to increasing SD. As ND increased serum LDL-C concentration of quails increased while level of uric acid decreased. The SD by ND interactions insignificantly affected all estimated criteria of quail hens. Conclusively, an optimal SD for laying quails is suggested to be 277.8 cm²/ hen for normal productive performance, egg quality and blood parameters. Increasing ND can alleviate the negative effects of high SD on laying performance of quails.