The line was extended from Imam-Khomeini to Baharestan Metro Station in 2004, and to Shahid Madani, Sarsabz and Elm-o-Sanat University in March 2006 with the intermediate stations, Darvazeh Shemiran and Sabalan, opening in July 2006.

[1] It was extended further from Elm-o-Sanat University to Tehran Pars in February 2009, and to Farhangsara in June 2010.

It then turns northwest, passing line 4 again at Darvazeh Shemiran, and Imam Hossein Square.

It then goes along Ayatollah Madani Street for 5.5 km (3.4 mi), until reaching Resalat Expressway, where it turns east again.

A 4.5 km (2.8 mi) long extension going eastwards from Farhangsara station is proposed.