The effects of Paenibacillus xylanexedens, alone or in combination with inulin and lactulose were evaluated on growth performance and intestinal histomorphology of male broilers. A total of 168 one-day-old male broiler chickens were randomly allocated to 4 experimental groups as follows: C, basal diet (control; without supplementation); P, 1x10(9) cfu/kg-feed P. xylanexedens; IN, 1x10(9) cfu/kg-feed P. xylanexedens and 1% inulin; LAC, 1x10(9) cfu/kg-feed P. xylanexedens and 0.5% lactulose. Addition of P. xylanexedens and synbiotics significantly increased broiler body weight gain (P<0.001) and feed conversion ratio (P=0.023) from 1 to 21 day of age. Moreover, a significant increase in body weight gain was observed when birds were fed with synbiotic supplemented diets during the overall experimental period (P=0.013). The addition of probiotic and synbiotics increased (P=0.047) villus height in ileum on day 42. Our results indicate that P. xylanexedens can be used as a probiotic feed additive in broiler diets and can improve broiler performance and intestinal histomorphology.