The aim of this study was to evaluate the effect of supplemented bay laurel (Laurus nobilis L. leaves to a conventional diet of laying Japanese quail on the performance and some egg quality. A total number of 60 and 54 days old laying type quails were distributed into individual cages for three different treatments. The control diet did not contain Laurus nobilis (LN) leaves (LNO) and the other diets were supplemented with 2 g (LN2) and 4 g (LN4) leaves kg(-1), respectively. The trial lasted for a total of 10 weeks. Supplemented leaves of LN (2 or 4 g kg(-1) feed) had no effect on any performance parameters, external and internal egg quality traits of quails. The diets have not changed the amount of egg yolk total cholesterol at 121 days old. However, egg yolk triglyceride concentration of quails fed LN4 diet was lower (p<0.01) than quails fed with the other diets at 121 days old. Besides, the amount of total cholesterol and triglyceride of egg yolk increased (p<0.01) in all of the groups with age. In egg yolk in the group receiving diet LN4, the level of palmitic acid was lower (p<0.05) and oleic acid was higher (p<0.05) than those of the other 2 groups at 118 days. Besides at that age, the level of palmitic acid was lower and oleic acid was >55, 76 and 97 days. There was no change in the other fatty acids. The changes in total saturated and total monounsaturated fatty acids were parallel with palmitic acid and oleic acid, respectively. Total polyunsaturated fatty acid content in the present study did not change with diet and age. The results of this study demonstrated that supplemented a conventional diet with LN could change some biochemical parameters of quail egg yolk.