Spinach (Spinacia oleraceaL. cv. Melody hybrid) leaf glycerate kinase (EC 2.7.1.31) was partially purified and characterized. The enzyme did not exhibit any absolute stereospecificity towards the two enantiomers of glycerate, but the affinity for the D‐isomer was 15‐fold greater. The enzyme exhibited a broad pH optimum of 7.5–9.0 and a requirement for divalent cation, satisfied by Mg2+. The reaction product was identified as 3‐phosphoglyceric acid. The observed high glycerate kinase activity together with its strategic localization exclusively in the chloroplast stroma are considered adequate for an efficient coupling of photosynthetic and photorespiratory carbon p