It was reopened on Friday during a ceremony attended by Iran’s Interior Minister Abdolreza Rahmani Fazli and his Iraqi counterpart Yassin al-Yassri.
During the ceremony, the Iranian minister said the Khosravi crossing would help pilgrims during Arbaeen processions.
Located in the western province of Kermanshah, Khosravi is one of several border crossings between Iran and Iraq. It lies 180 km away from the Iraqi capital of Baghdad.
The border crossing, which was closed for years due to security reasons, is expected to host a large number of Iranians planning to make a pilgrimage into Iraq this year.
In August, the Iranian and Iraqi interior ministers inked an agreement to reopen the border gate before the Arbaeen ritual ceremony.
Arbaeen, which is one of the largest religious gatherings in the world, comes 40 days after Ashura, the martyrdom anniversary of the third Shia Imam, Imam Hussein (AS).
Each year, a huge crowd of Shias flock to the Iraqi city of Karbala, where the holy shrine of Imam Hussein (AS) is located, to perform mourning rites.
Arbaeen falls on October 19 this year.
Before traveling to Khosravi for the reopening ceremony, Rahmani Fazli told reporters in the western city of Kermanshah that 51,000 Iranian pilgrims have traveled to holy sites in Iraq since the beginning of Muharram (September 1).
He said this shows a 200 percent increase compared to the same period last year.