In enzymology, prephenate dehydrogenase (NADP+) () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are prephenic acid and oxidised nicotinamide adenine dinucleotide phosphate (NADP<sup>+</sup>). Its products are 4-hydroxyphenylpyruvic acid, carbon dioxide, reduced NADPH, and a proton.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-CH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is prephenate:NADP+ oxidoreductase (decarboxylating). Other names in common use include prephenate dehydrogenase, prephenate (nicotinamide adenine dinucleotide phosphate), dehydrogenase, and prephenate dehydrogenase (NADP). This enzyme participates in phenylalanine, tyrosine and tryptophan biosynthesis.