Single crystals of Cf(IO3)(3) (1) were synthesized by the hydrothermal reaction Of CfCl3 and H5IO6, and the structure was determined with single-crystal X-ray diffraction. This structural determination of 1 represents the first for a trivalent californium compound containing oxygen coordination. This compound has been further characterized with the use of Raman spectroscopy and emission spectroscopy. Crystallographic data: Cf(IO3)(3), monoclinic, space group P2(1)/n, a = 8.7994(10) angstrom, b = 5.9388(7) angstrom, c 15.157(2) angstrom, beta = 96.833(2)degrees, V = 786.43(16) angstrom(3), Z = 4 (T = 295 K).