Biogas can be an important alternative energy source for the sustainable development of the energy sector. To understand the performance of the family-size biodigester in Bangladesh, a household level survey on randomly selected 360 biodigester adopters was conducted. It is evident from the study that adoption of biodigester at the household level is economically and environmentally viable. Most of the biodigesters were constructed for single household and production of biogas was sufficient for cooking for single household. About 35% of biodigesters generated surplus gas from which they earned money by selling the surplus gas. About 91% of the biodigesters were feed with cow dung, one of the optimal biogases producing substrates, which has easy access in their own households. The factor analysis suggests that the most important factors to make biodigester economically viable are: capacity of biodigester, availability of substrates, amount of investment for biodigester, and economic benefits derived from biodigester.