A 56-day study investigated the effects of Zymomonas mobilis treated sawdust on growth and economics of broiler chickens. Three hundred and seventy-five (375) day old unsexed marshal broiler chicks were allotted to five dietary treatments with 75 broiler chicks per treatment in a completely randomised designed experiment. Diets were formulated to include untreated sawdust (SD) and Zymomonas mobilis treated sawdust (ZSD) at 0, 50% and 100%. At the finishing phase (5-8 weeks), dietary treatments with 50% ZSD had higher daily weight gain and protein efficiency ratio (PER) and the lowest feed conversion ratio (FCR).