The precautionary principle is a well-recognised concept in the realm of international environmental law. The principle is a manifestation of the maxim in dubio pro natura which means in doubt, in favour of nature. The precautionary principle means the incorporation of caution in the decision-making process to prevent human activities from adversely affecting marine species and marine environment, even if there is no conclusive scientific proof linking those activities to the damage. The origin of this principle could be traced back to mid-1960s in Germany where the principle was applied in relation to pollution level. It first found its way into international law and policy as a result of German proposal made to the international North Sea Ministerial Conference in 1984. The concept of precaution received wide acceptance in international legal sphere through the UN Conference on Environment and Development held in Rio Conference in 1992. Principle 15 of Rio Declaration that deals with implementation of a precautionary approach has become a legal norm since then. Although the principle originated in the context of marine pollution, it is now applied across the entire range of international law. When maximum sustainable yield (MSY) approach of fisheries management was failing to effectively manage international fisheries, international community moved to sustainability approach and the precautionary principle was introduced into fisheries management. A number of international fisheries instruments including multilateral and regional fisheries treaties have incorporated this principle with a view to ensuring proper conservation of marine fisheries and marine biodiversity. The 1995 UN Fish Stock Agreement, a legally binding instrument for management of straddling and highly migratory fish stocks, and the 1995 FAO Code of Conduct for Responsible Fisheries, a non-binding legal instrument on fisheries management, have explicitly incorporated the precautionary principle. As Bangladesh has ratified the former and signed the latter, it bears the obligation to adopt the principle in the regulatory frameworks for the exploitation, management and conservation of marine fisheries. However, the existing regulatory frameworks for marine fisheries in Bangladesh do not adequately reflect the precautionary principle which has already attained the status of customary international law. All states and non-state entities, e.g. corporations, NGOs, regional fisheries management organisations, etc. are obliged to comply with the principle to ensure environmental protection. In Bangladesh, the Protection and Conservation of Fish Act, 1950 and the Marine Fisheries Ordinance, 1983 are two key laws dealing with the regulation of marine fisheries. The Protection and Conservation of Fish Rules, 1985 and the Marine Fisheries Rules, 1983 are two sets of Rules issued by the government for the implementation of the 1950 Act and 1983 Ordinance respectively. The National Fisheries Policy, 1998 and the National Fisheries Strategy, 2006 provide guidelines for the regulation of fisheries activities. The Department of Fisheries issues administrative orders time to time with a view to ensuring proper conservation of marine fisheries and marine ecosystem. The Ministry of Environment and Forests and the Department of Environment also have jurisdiction to issue rules, policy and administrative orders pertaining to marine environment. Except for the Marine Fisheries Sub-strategy under the National Fisheries Strategy, 2006, the legal and policy documents pertaining to regulation of marine fisheries do not reflect the precautionary principle. This 2006 Strategy with its eight sub-strategies was framed to help implement the National Fisheries Policy and to offer support to guide the sector. The Marine Fisheries Sub-strategy says that a marine fisheries management plan will be prepared based on existing information as a precautionary measure. However, the marine fisheries management plan has not been prepared till date. The decision-making process in fisheries management is also preventive and not precautionary. In July 2013, when the government decided to issue 25 new fishing licenses to trawlers for fishing in the EEZ, concerns were raised by many as to the merit of this decision of issuing new fishing licenses without conducting survey on the amount of stock. This decision by the government was considered to be a serious breach of precautionary norm as experts had been warning the government against a threat of overfishing in the Bay for quite a long time. The maritime area of Bangladesh has increased over the last few years through two successful boundary litigations with two neighbouring countries India and Myanmar. Now, the government of Bangladesh is mulling over new development plans for the marine fisheries sector. However, the government focuses generally on the exploitation of maximum benefits from the sea rather than the conservation of marine fisheries and marine biodiversity. Without conserving marine fisheries and marine biodiversity, the development in marine fisheries sector will not be sustainable in the long run. Therefore, it is about time the government of Bangladesh revised the age-old legal and policy frameworks for marine fisheries with a view to incorporating the precautionary principle not only in the substantive provisions, but also in the decision making process.