In enzymology, a 12beta-hydroxysteroid dehydrogenase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are 3alpha,7alpha,12beta-trihydroxy-5beta-cholanate and NADP<sup>+</sup>, whereas its 3 products are 3alpha,7alpha-dihydroxy-12-oxo-5beta-cholanate, NADPH, and H<sup>+</sup>.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD<sup>+</sup> or NADP<sup>+</sup> as acceptor. The systematic name of this enzyme class is 12beta-hydroxysteroid:NADP<sup>+</sup> 12-oxidoreductase. Other names in common use include 12beta-hydroxy steroid (nicotinamide adenine dinucleotide phosphate), and dehydrogenase.