Properties and Uses of Microemulsions is intended to provide the reader with some important applications and features of these systems. The intricate composition of microemulsions has made them applicable in many areas such as cosmetics, pharmaceuticals, food, agriculture, oil recovery, chemical synthesis of nanoparticles, and catalysts. An introductory chapter starts off with the description of these applications followed by methods of characterization. Thereafter, a few practical applications of microemulsions focusing on drug delivery, oil recovery, and formation of nanocatalysts are described followed by the third section discussing the theoretical and physical parameters predicting microemulsion properties. The use of spin-polarized paramagnetic probes, bending energetics, and study of self-propelled motion are some of the physical parameters employed to characterize the microemulsions.