The depolymerization behavior of poly(ethylene terephthalate) (PET) to terephthalic acid (TPA) and ethylene glycol (EG) in high-temperature liquid water is examined in a batch reactor. PET is completely depolymerized in water for 10 min at 573 K. The total energy to obtain TPA and EG from a continuous PET depolymerization process with high-temperature liquid water is estimated.