When the frequency used for excitation of Raman spectra of gases is high enough to reach the region of continuous absorption typical resonance Raman spectra may be observed. It is shown theoretically that the scattering formula for this case leads to selection rules at variance with the normal Raman effect, allowing an enhanced appearance of overtones. Also this resonance Raman effect has to be understood as a single quantum process. © 1969 Springer-Verlag.