Lysozyme is a potential alternative for antibiotic growth promoters in poultry production. The current study investigated the effects of different levels of lysozyme on broilers' performance, immunity, and gut health. A 35-day feeding trial was conducted with a total of 375 one-day-old Ross 308 chicks, which were randomly divided into five dietary treatments: CON) the basal diet; VIR) a basal diet with 200 mg/kg virginiamycin; and LYS) a basal diet with three levels from lysozyme (50, 100, 150 mg/kg diet, respectively). The results showed significant improvement in body weight gain, feed conversion ratio, dressing (%), and digestibility of crude protein in chickens fed 100 and 150 mg lysozyme than other groups. In comparison with the control group, the 150 mg lysozyme group had higher IgGand IgM levelsin serum compared to other groups. Dietary 150 mg lysozymes significantly increased the Lactobacillus and decreased the Clostridium perfringens and total coliforms in the cecum. Enhanced growth performance could be attributed to the positive effects of lysozymes on microflora modification, as well as immune response capacity and improving crude protein digestibility. Therefore, it can be concluded that supplementary up to 150 mg of lysozymes could be used as an effective alternative to antibiotics to promote productivity index and gut health in a broiler diet.