EPR spectra of Cu2+ and VO2+ ions in di-ammonium D-tartrate [(NH4)2C4H4O6] single crystals have been studied at room temperature and at 113 K in three mutually perpendicular planes. Both ions yield unexpectedly large number of lines. The spin Hamiltonian parameters are determined. A numerical technique together with a trial and error procedure is used to resolve the spectra. The principal g and the hyperfine (A) values of both of the ions were determined.