The focus of the present study is to isolate and identify the potential methanogenic bacteria from the cowdung procured from Namchi, South Sikkim, India. It was observed that, two bacterial isolates PRATIK-20 and VBC3 showed biogas (methane gas) production of 33.54% and 40.50% respectively using cow dung concentration 75% (w/v), inoculum 25% (w/v) at pH 7 and temperature 35°C in the fabricated anaerobic digester. Based on the 16S rDNA sequence, the bacterial isolates PRATIK-20 and VBC3 were identified as Bacillus sp. and Proteus sp. respectively.