Formation of primary paramagnetic point defects under low temperature X-ray irradiation have been studied by ESR and optical absorption in pure and thallium doped PbCl 2 single crystals. Besides Pb 2 3+ self-trapped electron (STEL) centers the PbCl 2:Tl crystals exhibit trapped-electron (PbTl) +-type centers. Based on production properties of paramagnetic centers it is suggested that besides forming Tl 2+ centers the holes are self trapped at pairs of neighbouring Cl − anions resulting in V k type centers with various orientation and length of the Cl–Cl axis.