This study's goal was to determine how yeast affected quail's growth. From one day to 42 day of age. One hundred and twenty quail chicks (a day-old), were initially fed a basic diet containing 23.8% protein and 2800 Kcal ME/kg diet for one week. At seven days old, the birds were randomly grouped into four sets, each with 30 quail chicks, divided into three replications with 10 chicks each. The chicks were then fed on four levels of yeast: zero (control), 1, 2, and 3 g/kg. The study found that feeding diets with 3 g/kg of yeast resulted in a significant increase in the average weight gain of birds, while those fed on zero, 1, and 2 g/kg had the lowest weight gain without significant differences between them. Birds fed on 3g/kg of yeast also had the best feed conversion ratio (FCR) in comparison to the other treatments. The results showed that yeast supplementation led to a significant increase in the blood levels of total protein, albumin and globulin, along with a decrease in serum total cholesterol and triglycerides compared to the control group. In contrast, birds fed on the control diet had higher serum Aspartate transaminase (AST) and Alanine transaminase (ALT) levels than those fed on yeast. The study did not find any changes in a serum albumin and globulin (A/G) ratio, the serum low-density lipoprotein (LDL), and high-density lipoprotein (HDL) due to yeast supplementation.