Aflatoxins are fungal metabolites by strains of Aspergillus (A.parasiticus and A.flavus) are produced. The clinical signs of aflatoxin poisoning include surgery autopsy, histological lesions and also create effects on the production of poultry flocks in experimental and natural occurrence have been reported in broiler chickens worldwide. The main signs of aflatoxin poisoning, loss of appetite, delayed growth, decreased body weight and food intake are reduced. Aim of this article is Study of performance broiler chickens fed of contaminated wheat by aflatoxin and neutralized by ammonia method. Thus, 280 male broiler chickens of Ross breed were randomly divided into 16 cages and feeding of recommended NRC and All of the experimental diets were same, except of wheat that was considered as fallow: Diet 1(control diet): contains Iranian healthy wheat (no aflatoxin), diet 2: contains ammoniated wheat, diet 3: contains wheat contaminated with aflatoxin (1 ppm) and diet 4: contains ammoniated wheat and contaminated with aflatoxin. According to the results increase in body weight in chickens fed the control diet (without aflatoxin) with ammoniated wheat and contaminated with aflatoxin (diet 4) was not significantly different (p<0.05) but body weight on diets contaminated with aflatoxin (diet 3) was significantly reduced (p<0.05). By the results, feed intake in broilers fed diets 3 (1 ppm aflatoxin) is lower than other groups (p<0.05).While, not significant differences between diets 2, diets 4 and control diet were observed (p<0.05). Lower feed intake and growth rate due to decreased activity of important enzymes in the digestion of carbohydrates, lipids, proteins and nucleic acids, and impaired and defects in some of the nutrient. Also The results obtained in this study were showed that aflatoxin in broiler diets due to increase relative kidney weight compared with chicks fed the diet has no aflatoxin (p<0.05). Ammoniate of wheat due to reduction and neutralization aflatoxin in wheat and ammoniated wheat that contaminate with aflatoxin has no effect on the relative weight of kidney (p<0.05).