This experiment was conducted to examine the effects of different levels of edible mushroom (Agaricus bisporus) in comparison with an antibiotic growth promoter (flavophospholipol) on intestinal morphology and microflora composition in broiler chicks. In this trial 180 nine-day-old mix sexes broiler chicks (Ross 308) were weighed and randomly allocated to 1 of 6 experimental treatments. Each treatment consisted of 3 replicates of 10 birds. The 6 treatments were as follow: Basal diet ( Basal diet+antibiotic (4.5 mg flavophospholipol/kg diet); and Basal diet supplemented with either levels of 5, 10, 20 or 30 g of dried mushroom/kg of feed. The morphological examinations of the intestine were carried out on 5-cm long excised segments from jejunum. The populations of Lactobacilli spp and Escherichia coli were enumerated in ileum by conventional microbiological techniques using selective agar media. The results of this trial showed that dietary mushroom supplementation did not significantly affect crypt depth, villous height and epithelial thickness except for the goblet cell numbers that decreased in the broilers fed diets containing 30 g mushroom/kg (p<0.05). The Lactobacilli spp. population in birds supplemented with mushroom at the level of 30 g/kg non significantly was higher than other groups at 45 d of age (p>0.05). Escherichia coli loads significantly decreased in broilers fed diets containing 5 g mushroom/kg (p<0.05). In conclusion, the results indicated that supplementing broiler diet with 30 g mushroom/kg could induce favorable influences on intestinal health of broiler chicks.