Vesicles in aqueous solution are well-known, but their counterparts in non-polar organic liquids (oils), referred to as “reverse vesicles”, are much less known. Reverse vesicles are spherical containers consisting of an oily core surrounded by a reverse bilayer. They could find analogous uses in encapsulation and controlled release, much like aqueous vesicles. However, few examples of robust reverse vesicles have been reported, and general guidelines for their formation have not been specified in the literature. We present a new route for forming stable unilamellar reverse vesicles in nonpolar organic liquids, such as cyclohexane and n-hexane (J. Am. Chem. Soc., in press). The recipe involves mixing short- and long-chain lipids (lecithins) with a trace of a salt such as sodium chloride. The ratio of short- to long-chain lecithin controls the type and size of self-assembled structure. As this ratio is increased, a spontaneous transition from reverse micelles to reverse vesicles occurs. SANS and TEM confirm the presence of unilamellar vesicles in the corresponding solutions. Average vesicle diameters can be tuned from 60 to 250 nm depending on the sample composition.