To woo householders into harnessing the cooking energy potential of biogas in order to solve the perennial cooking energy problems at household level in Nigeria, this paper carried out the engineering design requirement, and used the discounted cash flow micro-economic assessments to evaluate the 6.0 m 3 family-sized biogas project in Nigeria. The project has an initial investment cost of 41,088 Naira, annual expenditure of 5909 Naira and an annual benefit of 13,347 Naira. The NPV, IRR, B/C and payback period of financial analysis are 0.050 million Naira, 17.52%, 2.26 and 6.6 years respectively. This shows that the 6.0 m 3 family-sized biogas project using cattle dung as substrate in Nigeria has a good economic potential.