The microbiological potentials of using chicken droppings and banana peels for the production of biogas was investigated. Fermentation digesters were set up using sterilized and unsterilized samples with each having a set treated by heating at 800C for 1hour, cooled, filtered and dried and the other set untreated. The volatile fatty acid, organic matter, organic carbon, biogas production and microbial population were determined. The organic acid content was found to be directly proportional to the amount of volatile fatty acid produced hence the quantity of biogas. The microbiological analysis showed that the bacterial and actinomycetes populations increased from 2.4x104 to 6.0x107cfu/g and 1.6 x102 to 8.0x109cfu/g respectively by the 30th day. There was a reduction in the population of the cellulolytic bacteria. Biogas production was higher using co-substrates compared to when single substrates were used. The sterilized samples yielded no biogas indicative of microbial roles in biogas production.