As norm of customary international law, any breach of international law gives rise to obligation to make reparation. Polluter-pays principle (PPP), in environmental law, refers to the principle that if pollution occurs, the person or organization that caused the pollution should pay for the consequences of the pollution and for avoiding it in future. The principle insists that those who produce pollution should bear the costs of managing it to prevent damage to human health or the environment, the principle is also known as extended polluter responsibility (EPR). It is one of the precautionary principles for prevention of environmental damage. The polluter pays principle performs dual functions of preventing, or remediation, if pollution occurs. The principle started out as an economic principle adopted by Organisation for Economic Cooperation and Development (OECD). Internationally, the principle was first incorporated into Principles 21 and 22 of the Stockholm Declaration, 1973 and in The United Nations Conference on Environment and Development, 1992. The essence is to place further liability on the polluter and to alleviate the economic burden which pollution places on the authorities. PPP has been incorporated into domestic environmental legislation of most states. PPP and the general policy of internalising environment costs cannot be treated as a rigid rule of universal application, nor are the means used to implement it the same in all cases, therefore non-binding. The work appraises the Polluter Pays Principle (PPP) as a feature of customary international law.