A 33-day feeding trial involving 240 seven-day old broiler chicks was conducted to evaluate the effectiveness of a commercially available xylanase in wheat-based broiler diets in terms of production performance and feed cost per kg gain in weight. The five dietary treatments were: (a) Diet 1-com-based diet; (b) Diet 2 – wheat-based diet formulated using wheat ME value of 3,086 kcal/ kg; (c) Diet 3 - same as diet 2 plus xylanase; (d) Diet 4 - wheat-based diet formulated using wheat ME value of 3,271 kcal/kgi and (e) Diet 5 - similar to diet 4 plus xylanase. A commercially available xylanase was added to diets 3 and 5 at 200 g/ton of feed. At the end of the feeding trial, four broilers were randomly selected from each treatment for the determination of apparent metabolizable energy (AME) of the finisher diet. Significant improvements in body weight and gain due to xylanase addition were observed during the starter phase. Overall, there was no significant effect of treatments on body weight gain and feed consumption. However, the addition of xylanase to wheat-based diet improved feed efficiency of broilers to a level similar to that fed corn-based diet but better than those fed diets without xylanase. Ukewise, addition of xylanase significantly increased the AME of the finisher diet. The lowest cost to produce a kg gain in weight was observed in wheat-based diets with xylanase. The results indicate that supplementation of wheat-based broiler diets with commercially available xylanase would have positive effect on broiler performance.