Interfacial phenomena play a very important role in the casting process of steel melts. Typical examples are the emulsification/entrainment of slag into the steel melt or vice versa at the slag/melt boundary, the collision and agglomeration of oxide inclusions in the steel melt, the entrapment of inclusions at the refractory interface, which can eventually lead to the clogging of the submerged entry nozzle, as well as the local corrosion of solid silica at the metal/slag interface as a result of the Marangoni convection. The present work presents a short review of the influence of interfacial properties on the continuous casting process. In the subsequent section, the Drop Shape Analysis unit, an apparatus for the measurement of interfacial properties at high temperatures based on the sessile drop method will be presented. A project at the “Christian Doppler Laboratory for Fundamentals of Metallurgy in Continuous Casting Processes” focuses on the influence of interfacial phenomena on SEN clogging.