Rice straw (RS) contains a high amount of lignocellulosic materials which are difficult to degrade without thermal pretreatment. In the present study, co-digestion of municipal solid waste (MSW) and RS was carried out in three different ratios i.e., 1:1, 2:1, and 3:1 to get the maximum biomethanation potential and methane generation rate constant (k). The biogas and methane (CH4) potential increased by 60% and 57%, respectively for MSW and RS in the ratio 2:1 as compared to other combination. The values of k, biochemical methane potential (mu(b)) and sludge activity were measured as 0.1 d(-1), 0.99 CH4-COD/CODfed and 0.50 g CH4-COD/g VSS, respectively. The sludge activity was found to be 100% for 2:1 ratio. Co-digestion of RS with MSW can also optimize the C/N ratio which is an essential parameter in the anaerobic digestion process.