The plasma environments of Mars and Venus are determined by the interaction of the solar wind and radiation with their atmospheres. Beside electron impacts and photoionization, charge exchange processe have important specific consequences like the emission of X-rays and the production of Energetic Neutral Atoms which allow remote diagnostics of plasma processes. The aim of this session is to offer an opportunity to compare in situ and remote observations to model predictions of plasma processes in the Venusian and Martian environments. These two planets targeted by numerous missions could serve as test benches for future diagnostics of plasmas processes occuring nearby remote planets.