Abstract: This study was designed to determine the effect of enzyme supplementation and type of diet on gut microflora, gut pH and performance of broiler birds. A day – old (ANAAC 2000) broiler chick were used for the experiment. A total of 150 chicks were randomly distributed into three treatment diets having 5 replicates and 10 birds per replicate. The experiment was arranged as a complete randomised design and lasted for 49 days. The control diet contained maize –soya bean meal. The treatment diets had maize replaced with 200g/kg of wheat offal with and without enzyme supplementation. Data was collected on gut microflora population and pH in three sections (crop, ileum and caecum) of the gut. Performance related data were measured including weight gain, feed intake and FCR (feed conversion ratio). Gut microflora enumerated included coliform, Escherichia coli and Lactobacillus. Results obtained show that coliforms and E.coli were consistently higher (P<0.05) in the control than feeds supplemented with wheat offal with or without enzyme addition in the crop, ileum and caecum. The population of coliform and E.coli were lowest in the diet containing wheat offal and RoxazymeG2 G. The results also show that E. coli accounted for nearly 100% of total coliform in the GIT of the birds used for the present study. The overall pattern of the results indicated that the wheat offal in the poultry diet stimulated Lactobacillus growth which was further enhanced by the addition of enzyme. The stimulation of Lactobacillusby the diet containing wheat offal with or without enzyme coincided with the reduction in coliform and E. coli population, which suggests the efficacy of diet composition and enzyme supplementation in controlling pathogenic organisms in broiler chickens.The pH results of the digesta of the three treatments (i.e. diet compositions) where not significantly different (p >0.05) in the crop and ileum. But in the caecum, the pH was significantly different (p <0.05) being slightly more acidic than the control diet.Performance results showed that partial replacement of maize soya beans meal with wheat offal in the presence of Roxazyme G2 G increased weight gain, feed intake and feed conversion ratio, but all these differences were not statistically significant (p>0.05).