The marine biosphere represents a yet underexploited natural source of bioactive compounds, mainly of microbial origin. Among them, biosurfactants (BSs) are functional molecules, which are attracting an excellent interest thanks to their biocompatibility, versatility, and applications in several biotechnological fields. Biosurfactants are amphiphilic secondary metabolites produced by microorganisms. Marine bacteria have recently emerged as an upscale source for these natural products which exhibit surface-active properties, making them useful for diverse applications like detergents, wetting and foaming agents, solubilisers, emulsifiers and dispersants. Although precise structural data are often lacking, the already available information deduced from biochemical analyses and genome sequences of marine microbes indicates a high structural diversity including a broad spectrum of carboxylic acid derivatives, lipoamino acids, lipopeptides and glycolipids. This review aims to summarise biosyntheses and structures with a stress on low relative molecular mass biosurfactants produced by marine microorganisms and describes various biotechnological applications with special emphasis on their role within the bioremediation of oil-contaminated environments. BSs are secondary metabolism bacterial products which exhibit surface and emulsifying activities because of the hydrophobic a part of the molecule and therefore the hydrophilic water soluble end. they're produced extracellularly or as a neighborhood of the cell wall by a spread of yeasts, bacteria, and filamentous fungi from various substrates as sugars, oils, alkanes, and wastes The name surfactant derives from their surface chemical process , as they have a tendency to interact at the boundary level between two phases during a heterogeneous system by forming a movie which may change the properties (wettability and surface energy) of the first surface. they're mainly classified in BSs acting by reducing physical phenomenon at the air-water interface (biosurfactants), and BSs that reduce the interfacial tensions between immiscible liquids or at the solid-liquid interface (bioemulsifiers)