EPR spectra of Cr3+ ions doped in kainite single crystals were recorded at room temperature at X-band frequencies with 100 kHz field modulation. The principal values of g tensor and the zero field splitting parameters D and E were calculated from the EPR spectral studies. The measurements on chromium doped kainite show that the Cr3+ probe substitutes at magnesium sites. To confirm the orientation of the species, their direction cosines derived from EPR results are given. The results show that the crystal field symmetry around the Cr3+ ion in kainite single crystal is axial. (C) 2004 Published by Elsevier B.V.