The Iranian MPs met with Bahraini Parliament Speaker Ahmed al-Muslim.
Bahraini media said Muslim and Iranian Lawmaker Mojtaba Rezakhah held talks with each other over ways of expanding cooperation and coordination in the IPU.
This is the first meeting between the MP’s of the two countries since Manama cut ties with Tehran in January 2016.
The Bahraini government made the move after Saudi Arabia severed diplomatic relations with Iran and demanded Iranian diplomats leave Bahrain.
However, Iran and Saudi Arabia announced an agreement on Friday to resume diplomatic ties following a meeting by their security chiefs in Beijing. The rapprochement deal was mediated by Chinese President Xi Jinping.
Tehran and Riyadh had however held several rounds of talks to normalize their ties.
Iran and Saudi Arabia are going to reopen embassies in their capitals within two months.
Ties between Iran and Bahrain had soured after the 2011 unrest in the Persian Gulf kingdom which was cracked down by security forces there. Bahrain accused Iran of stoking tension in the country. Iran denied this claim.