Book excerpt: Surfactants are important in our daily life because they were widely used in household products, cosmetic, food and pharmaceutical industries as emulsifier, wetting agent, cleanser, foaming agents, solubilizers, conditioners, thickener and also to produce emollients. Therefore, nature of the surfactants is relatively important and is expected to be human friendly as the surfactants will be directly contacted with human. In recent years, biosurfactants such as glycolipids have drawn a large attention in the industrial applications especially in cosmetic and pharmaceutical industries. In this book, sucrose fatty acid ester which is a non-toxic and human friendly glycolipid surfactant was used in the preparation of olive oil-based emulsions for cosmetic and pharmaceutical applications. The results provide the information on the effect of the emulsion droplet size to the stability and rheological properties such as viscoelastic and viscosity of the emulsions.