Here, we report a facile approach for the rapid synthesis of bimetallic nanoalloys using cycle-controlled microwave-assisted polyol reduction, with an option of fixing the nanoalloys directly on graphene supports in a one-pot operation. Using Pt and Ni as the model noble and promoter metals, we show that Pt/Ni nanoparticles with diameters ranging from 2.8 to 4 nm can be readily synthesized within minutes.