Interest continues to grow concerning the application of microwave heating in chemical processes. This study shows that polymerization reactions such as emulsion polymerization in a polar solvent can be carried out rapidly and conveniently using microwave heating in glass reactors. It was found that a significant saving of energy and time was possible in the preparation of polystyrene. The heating rate was found to be influenced by the monomer-to-water ratio, magnetron power, the volume of the reaction mixture and the geometry of the container.