This study was conducted to evaluate effects of a sweet almond meal (SAM) as a source of protein on performance and immune responses of broiler chickens. Treatments consisted of different levels of SAM (7%, 14%, 21% and 28% of diet) and control diet that was performed in a completely randomized design in 42 days. Body weight gain (BWG) and feed intake (FI) were recorded weekly. Carcass characteristics and blood variables were measured on the 42 day of age. Immune response to sheep red blood cell (SRBC) was assessed at d 35 and d 42 (7 days after each injection). White blood cell count was done at d 28. The results showed that chickens fed 28% of SAM had lowest FI during the experiment. During grower period and also whole period of experiment, BWG was highest in chickens that consumed 7% SAM. Feed conversion ratio (FCR) significantly increased in chickens fed 28% SAM compared to the other treatments during grower period and also whole period of the experiment. The relative weight of thigh and breast significantly decreased and the relative weight of GIT increased by increasing levels of SAM in the diet. The concentration of cholesterol and LDL significantly decreased in chickens that consumed SAM in the diet. However, the highest glucose and HDL concentration were observed in chickens fed 28% SAM in the diet. Treatments did not have a significant effect on the immune response of broilers (primary and secondary SRBC antibody titres, relative weights of spleen and bursa of fabricius and white blood cell count) (p > 0.05). The results of this study show that a diet supplemented with SAM at the level of 14%, due to the improved FCR and decreased blood cholesterol and LDL concentration, can be a good replacement for soybean meal in broiler chicken's nutrition.