The over-dependence on fossil fuels as primary energy source has led to myriads of problems such as global climatic change, environmental degradation and various human health problems. Moreover, the recent rise in oil and natural gas prices has call for researches towards alternative energy sources. This study therefore investigates the digestion of cow dung and pig dung for biogas production at laboratory scales. The study was carried out through anaerobic fermentation using cow dung and pig dung separately as substrate and fresh cow rumen as source of methanogens. The fermentation medium was prepared with a total solid concentration of 8% fermentation slurry in four separate bio- digesters and fermentation carried out at temperatures between 27 – 35 °C and pH range of 6.2-6.8 for a period of 30 days. The biogas produced during this period was collected by water displacement method and subsequently measured and tested by flame test. The results showed that cow dung in bio-digesters A and B gave a cumulative average biogas volume of 4140 ml (138 ml day-1) while pig dung in bio-digesters C and D gave a cumulative average biogas volume of 4378 ml (145.9 ml day-1) within 30th days of fermentation. Keywords: Biogas, Cow-dung, Pig-dung, Methanogens, Bio-digester, Anaerobic fermentation.