Bio-surfactants are surface-active compounds are chemically synthesized and commonly used in almost every sector of recent industry that produced by several microorganisms such as; bacteria, fungi, and yeast varying in their chemical properties and molecular sizes. Bio-surfactants are classified into six main types based on their different properties and producer. There are five factors affect practically on the bio-surfactant production, such as; producer organism, carbon and (substrate) nitrogen sources, trace elements, temperature, and aeration. Due to their enormous diversity, they are considered interesting group of materials for many applications in several fields such as; agriculture, public health, food, health care, waste utilization, and in environmental pollution control such as; hydrocarbons degradation present in soil. Herein, these applications are covered and reviewed. Bio-surfactants are the most promising existing alternative products for further prospects in the future depends upon their availability, low-cost production, and stability in various industrial preparations. They present green solutions in food and therapeutics.