A significant amount of fish by-products is produced during fish processing. These by-products represent 20–80 percent of the fish and provide a good source of macro- and micronutrients. Yet they often go unutilized, when they can easily be converted into a variety of products including fishmeal and oil, fish hydrolysates, fish collagen, fish sauce, fish biodiesel and fish leather. The production of fish silage using organic acid is a good example of the simple and inexpensive conversion processes which can be employed. Fish silage production uses minced by-products or minced whole fish unsuitable for human consumption as raw material, before adding a preservative to stabilize the mixture – usually an organic acid such as formic acid. The process breaks down protein into free amino acids and small-chain peptides which have nutritional and antimicrobial properties, therefore, the fish silage can be used as healthy feed and fertilizer.The feasibility studies on fish waste management in Bangladesh, Philippines and Thailand outline existing good practices on the utilization of by-products and fish waste. Furthermore, the insights provided on the potential production and utilization of fish silage in each country are promising in terms of increasing the productivity of the fisheries sector, reducing post-harvest waste, increasing economic value and improving environment sustainability.