In enzymology, a terephthalate 1,2-cis-dihydrodiol dehydrogenase () is an enzyme that catalyzes the chemical reaction:
Thus, the two substrates of this enzyme are cis-4,5-dihydroxycyclohexa-1(6),2-diene-1,4-dicarboxylate and NAD<sup>+</sup>, whereas its 3 products are 3,4-dihydroxybenzoate, CO<sub>2</sub>, and NADH.
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 cis-4,5-dihydroxycyclohexa-1(6),2-diene-1,4-dicarboxylate:NAD+ oxidoreductase (decarboxylating). This enzyme participates in 2,4-dichlorobenzoate degradation.