In this paper, an overview is given of modeling activities going on in our research group, for describing the plasma chemistry and plasma–surface interactions in reactive plasmas. The plasma chemistry is calculated by a fluid approach or by hybrid Monte Carlo (MC)–fluid modeling. An example of both is illustrated in the first part of the paper. The example of fluid modeling is given for a dielectric barrier discharge (DBD) in CH₄/O₂, to describe the partial oxidation of CH₄ into value-added chemicals. The example of hybrid MC–fluid modeling concerns an inductively coupled plasma (ICP) etch reactor in Ar/Cl₂/O₂, including also the description of the etch process. The second part of the paper deals with the treatment of plasma–surface interactions on the atomic level, with molecular dynamics (MD) simulations or a combination of MD and MC simulations.