Soybean (Glycine soja var Beeson) formate dehydrogenase has been isolated, purified, and partially characterized by affinity chromatography. The enzyme is a dimer having a total molecular weight of 100,000 and a subunit weight of 47,000. It has activity over a broad pH range, is stable for months at 4 degrees C, and has K(m) values of 0.6 millimolar and 5.7 micromolar for formate and NAD, respectively.