The electron paramagnetic resonance of divalent Mn2+ions in K2Cd(SeO4)2.2H2O single crystals has been observed at room temperature using X-band microwave frequency. The Mn2+found to substitute for Cd2+exhibiting a single type of magnetic complexes which have been analyzed using the spin-Hamiltonian appropriate for rhombic symmetry. The forbidden doublets separations in M = +1/2 ↔ −1/2 and M = ±3/2 ↔ +1/2 transitions are obtained and compared with observed doublet separations.