Exopolysaccharides (EPSs) are secreted by both eukaryotes (fungi, phytoplankton, and algae) and prokaryotes (archaeobacteria and eubacteria). EPSs produced by bacteria include a broad range of chemical structures and may either be heteropolymeric or homopolymeric. Their molecular weights vary from 10 to 1000 kDa. Exopolysaccharides have multifarious applications in different fields of life. These EPSs are used as anticoagulant, immunomodulator, emulsifiers, anticancer and bioflocculants. They are widely used in food industry and bioremediation. This review article describes sources, synthesis, fermentation, extraction and applications of exopolysaccharides.