Pope Francis briefly lost his balance on the steps while boarding a plane as he left Greece.
He was caught by a gust of wind at Athens Airport before being helped on board by an aide.
Earlier, the Pope met students at a Catholic school in Athens in his final event of a five-day visit to Cyprus and Greece dominated by the plight of migrants seeking entry to Europe.
“When the temptation to close in on ourselves comes, look for others,” the Pope said.
He held brief talks on Monday with the Greek parliament's Speaker, Konstantinos Tassoulas, and with the leader of the main opposition party, Alexis Tsipras, who thanked him for “his unwavering defence of human rights and social justice".
During his visit, the Pope met the head of the Greek Orthodox Church and visited the Mavrovouni migrant tent camp on Lesbos, where he called their neglect of the “shipwreck of civilisation".
After his visit to the migration flashpoint, he celebrated mass for about 2,000 faithful in Athens, where he urged respect for the “small and lowly".
“I am trying to help you,” the pontiff told one group through his interpreter.
In his speech, he warned that the Mediterranean “is becoming a grim cemetery without tombstones” and that “after all this time, we see that little in the world has changed with regard to the issue of migration".
The root causes “should be confronted — not the poor people who pay the consequences and are even used for political propaganda”, he added.
According to the International Organisation for Migration, 1,559 people have died or gone missing attempting the perilous Mediterranean crossing this year.