The aim of this study was to investigate the effect of in-ovo injection of Lactobacilla Rhamnosus (0, 16x103, 32x103 and 48x103cfu) as probiotic source on hatching parameters and growth performance of quails. In this, a total of 400 quail hatching eggs, were randomly distributed among 4 experimental groups. Each experimental group contained 4 replicates of 25 eggs each. In-ovo injections of Lactobacilla Rhamnosus into quail eggs did not statistically affect incubation characteristics and some tissue weights. A high amount of Lactobacilla Rhamnosus injection into the breeder quail eggs negatively affected live weight and live weight gain. As a result, it can be said that low or medium levels Lactobacilla Rhamnosus injection into quail eggs have no effect on incubation and growth parameters of quails.