Palestinian President Mahmoud Abbas on Saturday unveiled a plaque and raised the Palestinian flag at a new Palestinian embassy in the Vatican.
The ceremony took place before Abbas meets with Pope Francis.
Diplomatic relations between the two sides were officially established two years ago.
The meeting between Abbas and Pope Francis will take place ahead of an international conference in Paris, where the Israeli-Palestinian conflict is scheduled to be discussed.
During the inauguration, Abbas reiterated calls to US president-elect Donald Trump to stop plans to transfer Washington's embassy in Israel to Jerusalem.
TRT World 's Josephine McKenna reports from Rome.
Osama Nazzal, Editor of the Ramallah-based Voice of Palestine, discusses Mahmoud's visit.