Extended basis set configuration interaction calculations on the excited state (C'(2)Delta) and several C'(2)Delta -X(2)Pi (r), transition bands of phosphorus monoxide have been performed. A variety of molecular properties are reported including: (i) spectroscopic constants; (ii) vibrational energies of the C'(2)Delta -state, transition band energies of several C'(2)Delta -X(2)Pi (r) bands and related Franck-Condon parameters; (iii) selected one-electron properties such as the electric multipole moments, O-17 nuclear quadrupole coupling, anisotropic hyperfine parameters, etc; (iv) vibrational electric dipole moments; (v) C'(2)Delta vibrational lifetimes through cascade and via electric dipolar decays C'(2)Delta --> X(2)Pi (r). Good agreement is obtained with the available limited amount of experimental data. The accuracy of the present results is discussed and compared to that obtained for the X(2)Pi (tau)-state and for excited states of homologous diatomics. (C) 2000 Elsevier Science B.V. All rights reserved.