Background and Objective: Poultry industry aims mainly to produce genetically superior animals with high productivity of egg and meat.On a commercial scale, the purpose of most quail genetic improvement programs is to select genetically superior birds for meat and egg production. The objective of this study was to investigate the effect of short-term selection through four generations of selection in Japanese quail on egg number at the first 90 days of laying, estimate genetic parameters of egg production traits and estimate the correlated response to selection. Materials and Methods: Data of 1,352 female Japanese quails were collected through five consecutive generations (base and four selected generations) to estimate genetic gain, depending on breeding values, for Age at First Egg (AFE), Body Weight at Sexual Maturity (BWSM), Weight at First Egg (WFE), Egg Number at first 90 days (EN90D) and Average Egg Weight (AEW). Results: Estimates of heritability for egg production traits were ranged from 0.17 to 0.26. Moreover, positive genetic correlations were detected (0.18 to 0.43) between all studied egg production traits, except the correlation between AFE and EN90D (-0.32). The contrast among estimates was significant (p<0.05), favoring the selected generations over the base. The cumulative selection response was favorable for all unselected traits with the superiority of the selected generations to the base generation. Conclusions: It can be concluded that early selection based on breeding value for a cumulative egg number at first 90 days of egg production can effectively improve the total egg production and other egg traits in Japanese quail through four selected generations.