The aim of this chapter is to provide a comprehensive overview of oral controlled release (CR) technology, based, to a large extent, on the author's experience and expertise from leading a CR centre of excellence for a multinational large pharma company and the internal and external collaborations or interactions that came with that role. The chapter discusses key considerations for CR formulation development, namely (i) the gastrointestinal tract, active pharmaceutical ingredient (API) attributes and manufacturability/quality by design (QbD), (ii) key process and formulation technologies and (iii) in vitro and in vivo evaluation of CR dosage forms. CR formulation technologies discussed are (i) hydrophilic matrix tablets, (ii) inert matrices, (iii) multiparticulate technologies, namely extrusion–spheronisation, direct pelletisation, dry powder layering, spray layering, hot-melt pelletisation, mini-tablets and multiple unit pellet system (MUPS) tablets, (iv) osmotic drug delivery systems and (v) proprietary and other technologies, including so-called diagnostic tools (i.e. Enterion™, IntelliCap®) and gastroretention technologies. While a single chapter can never provide universally applicable recipes or decision trees, it will hopefully give formulators a good overview to guide their own work in this exciting area of pharmaceutical formulation development.