Beschreibung:
We summarize the goals of photo-ionization modelling of nebulae ionized by Wolf-Rayet stars and discuss the methodology. We present some examples in different astrophysical contexts: ring nebulae around massive WR stars, planetary nebulae with [WR]-type central stars, and giant H II regions with WR stars. We discuss in more detail a work in progress (Stasińska & Schaerer 1999) on the galaxy I Zw 18.