This study was carried out to determine the effects of rations containing 0, 30, 60 and 90 ppm Yucca schidigera extract on egg production, feed intake, feed efficiency, egg quality and some blood parameters of quail. Two hundred and forty, eight-week-old Japanese quail (Coturnix coturnix japonica) were divided into one control group and three treatment groups of similar mean weight and egg production levels, comprising 60 quail each. A basal diet containing 18% crude protein and 2800 kcal/kg metabolic energy was supplemented with 0, 30, 60 and 90 ppm Yucca schidigera extract. The experimental period lasted 12 weeks. Yucca schidigera extract supplemented to the diet did not affect feed intake, egg production, feed efficiency, egg weight, white and yolk index, Hough unit or egg shell thickness, but reduced live weight (p < 0.05) and egg specific gravity (p < 0.01). At the end of the experiment, there were no statistically significant differences among the groups in serum total protein, albumin, triglyceride, cholesterol and inorganic phosphorus levels. Serum calcium levels were found to be significantly higher in the group fed rations containing 90 ppm Yucca schidigera extract (p < 0.01).