The deoxyuridine triphosphate nucleotidohydrolase gene from Arabidopsis thaliana was expressed and the gene product was purified. Crystallization was performed by the hanging-drop vapour-diffusion method at 298 K using 2 M ammonium sulfate as the precipitant. X-ray diffraction data were collected to 2.2 A resolution using Cu K alpha radiation. The crystal belongs to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 69.90, b = 70.86 A, c = 75.55 A. Assuming the presence of a trimer in the asymmetric unit, the solvent content was 30%, with a V(M) of 1.8 A3 Da(-1).