Transdermal drug delivery is in great demand and developing fast due to the various advantages over other conventional routes. Emerging as a safe, efficient transdermal drug delivery approach is the use of Transfersomes. These are hydrophilic lipid vesciles known to be ultra-deformable because of its ability to squeeze through the skin pores and penetrate the intact mammalian skin. Carrier systems like liposomes are unable to do this due to their larger size and inability of the vesicle walls to deform. This review describes the mechanism of transfersomal penetration through the stratum corneum, factors which influence these mechanism and formulation and evaluation of Transfersomes along with its scope in drug delivery. Transfersome consist of edge activators (mostly single chain surfactants) and phospholipids. Phospholipids form the outer rigid bilayer thus giving strength to the vesicles. The edge activators aid by weakning the lipid bilayer and increasing vesicle flexibility thus helping them penetrate through the stratum corneum. Thus selecting the optimum ratio of phospholipid and edge activator is very vital. Larger molecules can be easily administered by mere application onto the skin. It also reduces the dose required to show activity as it surpasses first pass metabolic pathway. Keywords: Transfersomes, Edge activators, Stratum corneum, Ultra-deformable, skin, transdermal delivery