Fish oil is an industrial product of high nutritional value because of its Omega-3 Polyunsaturated fatty acids content, currently valued for its beneficial effects on health. Several studies and advances were made since the year 2000 on fish oil extraction from several fish species. Extraction techniques range from traditional to more recently proposed technologies such as SFE, Enzymatic hydrolysis, PEF, UAE, HHP, MAE and pH shift method. Moreover, refining is performed to significantly lower certain undesirable Compounds that impair the oil's stability, quality, and acceptability, without losing the PUFAs. The high susceptibility of fish oils rich in omega-3 fatty acids to oxidation produces Undesirable taste and odour which limits the use of fish oils. So, Organic acids, radical Scavengers and antioxidants are used to maintain the oxidative stability of oils. On the other hand, monitoring the degree of oxidation in marine oils is a typical technique for regulatory and quality control objectives. In this review we discussed characterization of fish oil like GC-MS, ATR-FTIR and Raman main bands Even though various new techniques like MAE, UAE, PEF, SFE, etc are developed for improving oil recovery, the capital investment of these techniques is uneconomic in industrial-scale production. Since these modern techniques are cost ineffective most industries choose traditional techniques. However, SCF is primarily employed in the extraction of fish oil since it gives the highest recovery and safe product of all the other methods.