The decarboxylation or decarboxylative coupling reactions of carboxylic acids and their derivatives are some of the most powerful tools for the construction of platform molecules and valuable chemicals in organic synthetic chemistry. Additionally, microwave-assisted technology, which is strongly endorsed by industry in addition to academia, has been recognized as an alternative synthetic chemist's toolbox. Many decarboxylative reactions using microwave-assisted technology have been developed as an advanced strategy for sustainable organic synthesis for decades. This review highlights the recent developments in microwave-assisted decarboxylative reactions, including transition-metal-catalyzed and metal-free approaches.