This chapter provides a survey of microwave‐assisted organic reactions performed in both organic and aqueous solvents. Most organic reactions are performed using a homogeneous/heterogeneous catalyst for a few hours. The convenience of microwave irradiation has allowed these types of syntheses to be performed in only a few minutes. Employing microwave to an organic reaction could also improve the selectivity of a reaction to a specific product. The high‐throughput turnover of microwave‐assisted organic synthesis (MAOS) had also advanced the area of drug discovery in many ways. The development of aqueous homogeneous organic reactions (with respect to coupling) is due to the ability of microwave energy to increase the solubility of organic compounds in water. The Heck reaction is one of the most widely studied coupling system in organic chemistry. Other coupling reactions, such as the widely popular Suzuki coupling, have been tested for aqueous conditions under microwave.