¹School for Advanced Sciences, Vellore Institute of Technology, Vellore-14. Tamil Nadu. India DOI : 10.29228/jrp.203 Microemulsions are optically isotropic, thermodynamically mixture composed of two immiscible liquids (oil and water) stabilized by surfactant, sometimes along with cosurfactant with a diameter in the range 5-200 nm. They have emerged as novel drug delivery vehicle for controlled and sustained drug release for ocular, topical, parenteral, topical administrations. The ease of preparation and characteristics such as low viscosity, improved drug solubilization, long shelf-life make them as a unique candidate. Other than drug delivery, they possess a wide range of applications in the field of biotechnology, enhanced oil recovery and cosmetics. The core intent of this review article is to bring out details on types of microemulsions, structure, physiochemical characteristics, thermodynamic stability and applications in various fields. Keywords : Microemulsions; Thermodynamically stable; Bioavailability; Self-emulsification; Hydrophilic-lipophilic