The hydroponic fodder industry has been extensively advertised and has a renewed interest among scientists and livestock producers. This study was designed to evaluate the nutritional impacts of hydroponically sprouted barley (HSB) as a feed supplement on egg production, egg quality, reproductive performance, and blood analyses of laying Japanese quails. Seventy-two laying Japanese quails, housed in twelve battery cages, each of six birds (two males + four females), were assigned randomly to three feeding treatments: (i) a commercial diet provided ad libitum (control), (ii) ad libitum diet plus fresh HSB (ad lib + HSB), and (iii) a restricted feed amount of the same diet (15% lower than that of the control), plus fresh HSB (RST + HSB). The data collection continued for 11 weeks. The fresh-8-days HSB contained 163.8 g/kg of dry matter, with crude protein and aNDFom contents of 230.3 g/kg DM, and 267 g/kg DM. Compared to the control diet, the ad lib + HSB had a higher (P < 0.05) egg laying rate (0.963 vs. 0.888), fertility (0.921 vs. 0.886), number of hatched chicks, relative weights of the gizzard and testis, and longer oviducts. On the other hand, the RST+ HSB treatment maintained a similar egg laying rate and fertility to those of the controls (P > 0.05), but with a lower daily egg mass (10.84 vs. 11.29 g egg/female/day) and hatchability (0.582 vs. 0.671). The egg quality variables, activity of blood total antioxidant capacity, and plasma contents of cholesterol, free fatty acids, total protein and globulin were not affected by the treatments. To conclude, the feed restriction (-15% of feed amount) did not increase the HSB intake, and the ingested HSB amount did not completely compensate the reduction in nutrient intake, which led to reduced daily egg mass, fertility and hatchability. Providing the ad libitum fed laying Japanese quail with fresh HSB significantly increased the egg laying rate, relative weights of gizzard and testis, fertility and number of hatched chicks/female, but did not affect egg quality indices or blood analysis.