There is growing demand in the food industry for natural ingredients to fabricate ‘clean label’ products. This article provides a review of recent studies on the identification, characterization, and utilization of natural food-grade emulsifiers, such as proteins, polysaccharides, phospholipids, and saponins. Particular emphasis is given to relating the structural properties of these emulsifiers to their ability to form and stabilize emulsions. The influence of environmental stresses, such as pH, ionic strength, and temperature, on the performance of natural emulsifiers is discussed. This information should facilitate the rational selection of natural emulsifiers for applications in emulsion-based food, beverage, cosmetic, and pharmaceutical products.