The production of D-glycerate from L-tartrate was investigated with cells of Pseudomonas sp. group Ve-2, which produce L-tartrate decarboxylase. The production with intact cells had several advantages over production with the cell extract; no addition of NAD+ is required, the substrate inhibition for the reaction is diminished, and the reaction can be done at higher temperatures than the reaction with cell extract. The culture conditions and the reaction conditions were optimized. The maximal activity was obtained when the cells were cultured at 30°C for 24 hr in a medium containing 1.0% potassium L-tartrate, 0.05% NH4NO3, 0.2% yeast extract, 0.3% K2HPO4, 0.01% MgSO4•H2O, and trace elements (pH 7.5). The amount of D-glycerate produced reached 106 g/l at 45°C after incubation for 45 hr, with a molar yield of almost 100%.