The Clausius–Clapeyron equation is used to do a comparative study of the properties of the clouds that form in planetary atmospheres. Simple static atmospheric models for various planets, the satellite Titan, and the extrasolar planet HD209458b are used together with the saturation vapor pressure curves of the different kinds of molecules to determine the pressure, density, and scale height of the clouds in each body. This application of the Clausius–Clapeyron equation extends our knowledge of terrestrial water clouds to different exotic clouds present in other planets.