A sago-based gel polymer electrolyte (GPE) was prepared by mixing native sago with potassium hydroxide (KOH) aqueous in order to investigate the applicability of GPE to zinc-air (Zn-air) battery. The viscosity and conductivity of the sago GPE were evaluated using varying sago amounts and KOH concentrations. The viscosity of the sago GPE was kept as a reserve in the region of ~ 0.2 Pa s as the KOH concentration was increased from 2 to 8 M. Sago GPE was found to have an excellent ionic conductivity of (4.45 0.1) x 10-1 S cm-1 with 6 M KOH. GPE was also employed in an experimental Znair battery using porous Zn electrode as the anode. The battery shows outstanding discharge capacity and practical capacity obtained of 505 mA h g-1.