Hollow microspheres are spherically symmetrical particles consisting of at least two phases. Their sales are continuously increasing because of a large number of well-known and new applications. While most of the current needs for hollow microspheres are met by inorganic byproducts of combustion processes (cenospheres), the fabrication of tailor-made hollow sphere structures by processes like spray-drying as well as dripping, emulsion and suspension techniques is gaining more and more interest. Surface phenomena play an important role as far as formation, properties and stability of hollow microspheres are concerned. Template techniques can be used to yield structures that have not been available so far. Modeling and simulation of the formation processes are useful tools to understand the formation mechanisms and to simplify the scaleup.