A new Mg2+ -ion conducting polymer electrolyte based on Poly (ethylene glycol) complexed with Mg(CH3COO)2 has been prepared using solution-cast technique. DSC, Composition-dependent conductivity at different temperatures, dielectric studies, and transference number measurements have been performed to characterize the polymer electrolytes. The DSC measurements show decrease in melting point with increase in salt concentration. Out of five different compositions studied, the 85PEG: 15Mg(CH3COO)2 polymer-salt complex showed the highest conductivity with σ = 1.07 x 10-6 S/cm at room temperature (30°C). The transport number measurements have shown that the electrolyte is an ionic conductor. Using the electrolyte, an electrochemical cell with the configuration Mg/(PEG+Mg(CH3 COO)2)/(I2 +C+electrolyte) has been fabricated and its discharge characteristics studied.