Fermentation is one of the oldest food-processing techniques. It provides a way to preserve food products, enhance nutritive value, destroy undesirable factors, improve the appearance and taste of food, reduce the energy required for cooking, and make a safer product. Fermented fish products are important traditional foods in many countries of the world, particularly in Asia. An attempt has been made here to elucidate the important features of different fermented products, including nutritional aspects, health benefits, safety concerns, and recent developments. This revealed an important feature of fermented products, in-process fortification with different essential amino acids, vitamins, and bioactive peptides. It has been also revealed that fermented foods are safe to consume because of their probiotic effect against microorganisms, and they play an important role in reducing the risk of cancer and other degenerative diseases. This article also highlights important Asian fermented fish products and production techniques, including new concepts in production from other regions.