This thesis is inspired by the long lasting media and politicians’ discussions about building the Nord Stream Pipeline in the Baltic Sea. Nobody disagrees about the need of the pipeline between Russia and Europe, but there are many uncertainties about the route through one of the most polluted seas in the world and a route passing by Natura 2000 sites. That is why, the main idea was to show that current environmental instruments and legislation are not strong enough to guarantee environment protection and rights of future generations, especially, where business and politics are involved. It would be ideal for a strong mechanism, controlling activities, to be created, which could prohibit excessively dangerous projects in global commons like the seas. This thesis is a research of the specific Environmental Impact Assessment (EIA) procedure in the international Nord Stream Project and analyzes whether the involved states acted with due diligence in this specific case. The following issues were analyzed: EIA treaties and documents, EIA procedure, case law and customary rules of acting with due diligence and Aarhus Convention.