Rau began his visit on Saturday evening following an invitation from the Iranian authorities, the first such trip since 2014.
Poland has provided military support to Ukraine, while Iran has refrained from condemning Russia’s invasion of its neighbor.
Rau and Amir-Abdollahian will sign “a cooperation agreement on culture, education, science, sport, youth and the media”, the Iranian minister said.
Rau’s trip also has a strong symbolic aspect.
Polish media said the minister paid a visit Sunday to a Tehran cemetery where many of his fellow countrymen who had been deported to the Soviet Union at the start of World War II and later found refuge in Iran are buried.
“Remembering the past, we cannot forget the people who suffer today due to the atrocities of war,” Rau said, according to Polish agency PAP.
“Surrounded by around 2,000 graves of soldiers and civilians, we pay homage to the Poles who were deported to labor camps in the Soviet Union and who died” after leaving the camps, PAP quoted Rau as saying.
Almost 120,000 Poles, more than half of them children, found themselves on Iranian territory.
Their death rate was high due to poor health.
“We preserve these dramatic memories, and at the same time we are proud of the courage of the Polish soldiers who fought for a free Poland,” he added.