This study was carried out to determine the effect of supplementing different levels of yeast (Saccharomyces cerevisiae - Sc) in the diet on the growth performance, carcass traits, and some blood parameters of Ross broiler chicks until 42 days of age. Ninety-six Ross broiler chicks, one day old, were randomly divided into four nutritional treatments. Each group consisted of three replicates, each holding eight chicks. The treatments contained 0% (control), 0.25, 0.5, and 0.75% of Sc, respectively. All birds were raised in wire-floored batteries under the same environmental and management conditions. Data were collected for body weight (BW), body weight gain (BWG), feed intake (FI), and feed conversion ratio (FCR); which were determined at 3 weeks and 6 weeks at the end of the experiment (42 days of age). At the end of the experiment, carcass yield percentage of heart, liver, gizzard, and abdominal fat, and some blood parameters were recorded. The results showed that chicks fed the control diet achieved the highest values in BW and BWG (P<0.05) compared to the other treatments. Feed conversion ratio and feed intake of broilers fed diets with yeast supplementation at dosages of 0.25, 0.5, and 0.75% showed non-significant changes. Results indicated non-significant changes in total protein, glucose, triglyceride, and urea in broilers fed yeast supplementation at doses of 0.25, 0.5, and 0.75%. It is concluded that dietary Sc could improve carcass characteristics and some blood parameters in broiler chicks. At the same time, there were no effects on production performance characteristics.