Influenced by development projects in its peripheral area, the Urmia Lake is facing dramatic ecological changes prone to an environmental tragedy. The environment does not recognize political borders. Any environmental change poses positive or negative implications inside the country as well as in its regional vicinity. At international level, different legal instruments on ecosystems, including ecosystem of wetlands, put certain commitments and obligations on states. Due to trans-border implications of ecosystem changes, international community decided to deliver financial aides and technical assistance to requesting states. Three international legal instruments; Ramsar Convention, Biological Diversity Convention, and the UNESCO Man and Biosphere Program are among international environmental instruments mostly applicable to Urmia Lake. This paper focuses on the ways and means the Iranian government could take the international support to address the Urmia Lake tragedy.