About 70-75% of drugs is taken orally and is found not to be as useful as desired. A self-micro emulsifying drug delivery system (SMEDDS) is a drug delivery system that uses a micro-emulsion achieved by chemical rather than mechanical means. Micro-emulsions have significant potential for use in drug delivery, and SMEDDS are the best of these systems. SMEDDS are of particular value in increasing the absorption of lipophilic drugs taken orally. SMEDDS are mixtures of natural or synthetic oils, solid or liquid surfactants, or alternatively, one or more hydrophilic solvents and co-solvents/surfactants that have a unique ability of forming fine oil-in-water (o/w) micro emulsions upon mild agitation followed by dilution in aqueous media, such as GI fluids. SMEDDS spread readily in the GI tract, and the digestive motility of the stomach and the intestine provide the agitation necessary for self-emulsification. SMEDDS can be encapsulated in hard or soft gelatin capsules or can be converted to solid state (Solid SEDDS/SMEDDS). This review article provides an overview of SMEDDS and its advantages over conventional dosage forms. Keywords: SMEDDS, Micro-emulsions, Co-solvent