In this study, exclusive affect of microwave mediated synthesis on the physicochemical and electrochemical properties of α-MnO2 have been differentiated from that of α-MnO2 synthesized in conventional-reflux method. The TG, XRD, BET and SEM analyses show improved physicochemical properties like additional lattice K+ ions, better crystallinity, high surface area (155 m2 g−1) as well as pore volume (0.67 cm3 g−1) and hierarchical porous ball-like morphology of the microwave-synthesized α-MnO2. The CV studies show lower polarization resistance and higher rate pseudocapacitance (258 Fg−1 at 100 mVs−1) of microwave-synthesized α-MnO2 as compared to its reflux-synthesized counterpart (168 Fg−1 at 100 mVs−1). The CP studies show better high rate charge-discharge performance (146 Fg−1 at 16 Ag−1), longer cyclic stability (91.4% capacitance retention after 400 charge-discharge cycles at 16 Ag−1) and higher Coulombic efficiency (∼100%) of microwave-synthesized α-MnO2 as compared to the reflux-synthesized sample (80 Fg−1 at 16 Ag−1; 74.1% capacitance retention after 400 charge-discharge cycles at 16 Ag−1; 85% Coulombic efficiency). Further, due to facile mass transfer in the perfectly porous matrix, the microwave-synthesized α-MnO2 shows lower equivalent series resistance and better frequency response (higher specific capacitance at elevated operating frequency) as revealed from the impedance studies.