Microwave irradiation was applied to synthesize poly(epsilon-caprolactam-co-epsilon-caprolactone) directly from the anionic catalyzed ring opening of two cyclic monomers, epsilon-caprolactam and epsilon-caprolactone using a variable frequency microwave furnace, programmed to a set temperature and controlled by a pulsed power on-off system. Dielectric properties of epsilon-caprolactam, epsilon-caprolactone, and their mixture were measured in the microwave range from 0.4 to 3 GHz, showing that, both epsilon-caprolactam and epsilon-caprolactone exhibited effective absorption of microwave energy to induce a fast chemical reaction. The microwave induced anionic copolymerization of epsilon-caprolactam and epsilon-caprolactone generated copoly(amide-ester)s in yields as high as 70%. Conventional thermal and microwave copolymerization studies were also conducted for comparison with the microwave results. These studies demonstrated that an effective and efficient microwave method to copolymerize epsilon-caprolactam with epsilon-caprolactone in higher yield, higher amide content, and higher T-g's, relative to the thermal process, has been developed.