In this work, we have studied bismuth as a dopant in graphene using density functional theory (DFT). We find that bismuth is weakly physisorbed within DFT. On the other hand, we show that bismuth n-dopes graphene when it is substitutional. We observe that local density approximation results give higher substitutional energy than that of generalized gradient approximation. The electronic structure of graphene is changed when Bi is substitutional.