Self nano emulsifying drug delivery systems (SNEDDs) gained much attention in the last decades since, such systems considered one of the most favorable and efficient approaches to enhance solubility, increase drug absorption and hence, enhance its oral bioavailability of poorly water soluble (lipophilic) drug moieties. Owing to their unique properties and advantages over the other conventional dosage forms, many literatures investigate the change physicochemical properties, pharmacokinetic and pharmacodynamics of self emulsifying formulation compared to both pure drug and its conventional dosage form and always reported significant improvement using SNEDDs. This review discus the composition, advantages and mechanism of action of liquid SNEDDs and some techniques used for solidification of liquid formulations to overcome its drawbacks.