The hydrogenase maturation protein HypE is involved in the biosynthesis of the CN ligands of the active-site iron of [NiFe] hydrogenases using carbamoylphosphate as a substrate. Here, the crystallization and preliminary crystallographic analysis of HypE from Thermococcus kodakaraensis KOD1 are reported. Crystals of HypE (338 amino acids, 35.9 kDa) have been obtained by the sitting-drop vapour-diffusion method using 2-methyl-2,4-pentanediol (MPD) as a precipitant. The crystals belong to space group P2(1)2(1)2, with unit-cell parameters a = 88.3, b = 45.8, c = 75.1 A. There is one HypE molecule in the asymmetric unit. A complete native X-ray diffraction data set was collected to a maximum resolution of 1.55 A at 100 K.