Microwave (MW) irradiation is a simple and effective nonconventional heating method and is well-known in the field of metal-organic framework synthesis. In this paper, we report, a rapid microwave-assisted method for the synthesis of a UTSA-16 metal-organic framework. This process noticeably reduces the synthesis time from the 48 h required in traditional synthesis to 4 h. The synthesis of UTSA-16, whose formation was confirmed by X-ray diffraction analysis, was optimized by varying the synthesis time from 0.5 to 8 h. The UTSA-16 prepared with a reaction time of 4 h (4 h-UTSA-16) showed excellent CO2 adsorption capacity of 5.5 mmol/g at 298 K and 1 bar with a CO2/N-2 sorption selectivity of 104, which is even higher than those reported for UTSA-16 samples prepared by solvothermal methods. The stability of UTSA-16 in humid air and acid gases was investigated by exposing it to humid air, as well as SO2 and NO2 gases, for 6 days. The UTSA-16 was very stable, showing no changes in the CO2 capture capacity and FTIR spectra after exposure to NO2 in humid air.