We have studied the Cu2+ ion doped orotato(nicotinamid)cobalt(II) complex by using EPR spectroscopy and X-ray diffraction. The single crystal is triclinic with the space group P (1) over bar. The unit cell dimensions of the crystal are a = 7.2785(4) angstrom, b = 10.2349(5) angstrom, c = 12.7372(6) angstrom, alpha = 69.297(4)degrees, beta = 74.791(4)degrees and gamma = 76.995(4)degrees, with Z = 2. We analyzed the EPR spectra of both single crystal and powder of the complex at room temperature. EPR analysis indicates the presence of only one Cu2+ site. We obtained the spin Hamiltonian parameters from the single crystal data for the complex. The spin Hamiltonian parameters are g(x) = 2.032, g(y) = 2.116, g(z) = 2.319, A(x) = 28 G, A(y) = 66 G, A(z) = 126G. These data indicate that the symmetry of paramagnetic center is rhombic. We constructed the ground state wave function of the Cu2+ ion. (C) 2015 Elsevier B.V. All rights reserved.