This research aims to investigate the potential of the municipal garden waste as a new precursor to generate activated carbon by CO2 activation. TGA analysis shows the distinctive thermal degradation nature of garden waste. The activation of the garden waste enhanced its surface area where well-developed internal micro-mesoporous structure is also noticed. The results suggest that most of the volatiles decomposed at temperatures beyond 450 °C. A decrease in char yield, increase in surface area and pore volume and weakening of oxygen and hydrogen-containing groups were observed at higher pyrolysis temperatures. Raman and XRD support the amorphous and porous graphitic structure of carbon. Carbonization temperature of 500 °C and activation temperature of 800 °C were shown to produce the better-quality AC where highest surface area of 363.32 m2/g and highest pore volume of 0.095 cm3/g was achieved. Compared to the pyrolysis temperature, pyrolysis steps did not have notable contribution to the AC characteristics.