This study aimed to decrease the cost of laying rations by lowering protein as it's the most expensive constituent in the diet. So, the research stated to investigate the effect of incorporating protease and/or formic acid as feed additives into a low protein isocaloric diet of laying Japanese quail hens on the productive performance, some egg quality parameters and economic efficiency. It was performed on 120 of 5–6-week-old healthy Japanese quail hens (weighed 268g7.06±) and randomly distributed into five groups (3 replicates per group). G1 (control with basal layer quail diet 20% protein), G2 (17% protein diet without protease enzyme or formic acid), G3 (17% protein diet + 0.05% protease enzyme), G4 (17% protein diet + 0.5% formic acid), G5 (17% protein diet + 0.05% protease enzyme + 0.5% formic acid). The experimental period lasted for 12 weeks with two weeks of adaptation before this period. For each replicate, daily egg number, daily egg weight, and egg mass as well as weekly feed intake were recorded. At the end of each week, eggs were collected from each replicate to evaluate egg quality. Mean egg production, egg albumin %, eggshell % and egg yolk % in all groups do not differ significantly with control but G2 was numerically higher than control in egg production, egg mass, FCR, egg shell %, egg yolk % and feed intake. G2 significantly has the heavier egg weight among groups (p < 0.05) as the average egg weights were 11.77g and 12.48g in control and G2 respectively. G3 was being the highest in feed intake and egg albumin percent than the other groups. G4 was being the highest in eggshell percent. Triglycerides per the whole yolk were lower in all groups than in the control. Cholesterol (mg)/whole yolk was low in G2 and G3. FCR was improved in G5. G2 had the highest net revenue and economic efficiency (48 LE&114.3%) in compare with control (46 LE&106.98%), while the values were 47.1LE&107.3%, 43.3LE&101.4% and 46.2 LE&105.5% for groups G3, G4 and G5 respectively. It could be concluded that feeding laying Japanese quail hens on diet containing 17% protein without protease enzyme or formic acid did not differ significantly from those fed on a control diet containing 20% protein. Moreover, it showed the highest net revenue and numerical improvement than the control group regarding egg production, egg mass, FCR, eggshell %, egg yolk %, and cholesterol in egg yolk.