The United Republic of Tanzania adheres to a dualist system concerning the application of international law. In a dualist framework, international treaties and agreements do not automatically become part of domestic law upon ratification; instead, they require specific legislative action to be incorporated and thus enforceable within the national legal system. ​

Under Tanzania's current constitutional arrangement, international treaties must undergo a formal domestication process to acquire the force of law within the country. This means that after the executive branch ratifies an international treaty, the Tanzanian Parliament must enact corresponding legislation to transform the treaty's provisions into national law. Without such legislative action, the treaty's stipulations hold no legal authority domestically.

This dualist approach underscores the separation between international obligations and domestic legal applicability, ensuring that international commitments are scrutinized and approved through the national legislative process before affecting the rights and duties of individuals within Tanzania. Consequently, for international law to be operational within Tanzania, it must be explicitly adopted through domestic legislation, reflecting the country's adherence to the dualist doctrine.