The present review deals with the progress of Polysorbates (Tween) based microemulsions in drug delivery. PEGylated Sorbitan Fatty Acid Esters (Tweens/Polysorbates) are one of the most used non-ionic surfactants. Particularly, Polysorbates based microemulsion has been widely used for enhancing solubilization of poorly soluble drugs. This article deals with underlying the preclinical factors which affect the solubilization efficacy of Tween formulations, implication of pharmaceutically accepted vectors in terms of absorption, bioavailability, biological fate and potential toxicity. Antimicrobial activity of Tween microemulsion formulations has also been addressed emphasising the role of Tween. The review contains comprehensive knowledge/literature related to physicochemical parameters and biological fate of different Polysorbates and takes into account all the parameters and observations that make Tween a very convenient and safe choice for the use as pharmaceutical excipient for microemulsion formulations.