The crystal structure of urea-(+)tartaric acid (UT), C4H6O6-CH4N2O, was determined using a single crystal diffractometer. The compound crystallizes in the orthorhombic system with a = 5.056(2) Angstrom, b = 9.824(3) Angstrom, and c = 1 7.229(6) Angstrom; the space group is P2(1)2(1)2(1), Z = 4, and D-c = 1.63M(g) m(-3). The final R = 0.0304 (wR = 0.0331) for 932 reflections. The asymmetric unit in the structure contains a urea and a (+)tartaric acid molecule, which are connected by a strong O-H ... O hydrogen bonds. The packing of the molecules in the crystal is stabilized by a three-dimensional network of hydrogen bonds.