Tadic made the appeal at a meeting with the head of the UN refugee agency's special mission in Serbia-Montenegro. Monday was also the fifth World Refugee Day.
He said his country is housing over 100,000 refugees, whose living conditions have not improved over the last 10 years.
In wars following the collapse of former Yugoslavia, a large number of refugees fled into Serbia-Montenegro from Croatia and Bosnia-Herzegovina. Serbia-Montenegro now has the largest number of refugees in Europe.
Serbia's statistics bureau reported that over 140,000 people registered as refugees between October 2004 and January 2005. The number peaked 10 years ago at 500,000.
The Sarajevo Declaration expected Serbia-Montenegro, Croatia and Bosnia-Herzegovina to solve the refugee problem by the end of 2006.