[en] We present experimental and theoretical results on CoO Resonant Raman Scattering (RRS) with excitation at many values in the whole CO^2-L_2,3 region and with a final state containing a Co-3s hole. The theory includes the final state interaction between the configurations with one 3s hole and that with two 3p holes (Cl). A cluster calculation with Cl reproduces the experimental results with excitation spanning the whole L₃ region. In the L₂ region the theory reproduces the evolution of the RRS doublet at higher outgoing energy. On this basis the role of Cl and of the ligand hole effects are discussed vs. the excitation energy. At least 5 eV above the L₃ threshold the experimental results show also a non-dispersive component with intensity rapidly increasing with the excitation energy. The position and the shape of this component is well reproduced by a model calculation accounting for all possible partitions between the transitions to the continuum and to the 3d-shell. However the intensity of the calculated non-dispersive component is about an order of magnitude smaller than the measured one. The implications of this fact in terms of the dynamics of the intermediate state are outlined. (author)