It is colored deep purple on the maps and route signs.

M5 is the second rapid transit line on the Asian side of Istanbul, the other in service since August 2012, the M4.

The construction of the 20-kilometre-long (12 mi) line in the west–east direction with 16 stations between Üsküdar and Çekmeköy, and its connection line to the depot with 3 km (1.9 mi) length began on 20 March 2012.

According to news in Turkish TV in November 2016, half of the M5 line (Üsküdar - Ümraniye) would open in January 2017, with driverless trains, and then in early 2017 the new opening date was stated to be 22 March providing there are no further delays.

All stations have protective barriers with automatic doors, opening only when the train is stopped at the platform.