In CaMoO4, crystals with oxygen deficiency thermally stimulated depolarization (TSD) currents are investigated in dependence on polarization time as well as on polarization temperature. The results can be well understood on the base of dipole orientation. Optical absorption measurements yield a band near 460 nm and another very broad one at around 850 nm, either band showing anisotropic absorption of plane polarized light. From molecular orbital theory the infrared band is assumed to be due to a transition within (MoO4)3− centre. The other absorption band possibly arises from oxygen vacancies which have trapped one or two electrons. The gradual disappearance of either band due to annealing procedure can be correlated to that of the TSD signal. Thus the proposed models of dipole centres involve absorbing defects, too.