The initial Metrolink network was formed of two converted railway lines, linked across the city centre. Since opening in 1992, one extension has been completed and several more are planned.

The present Metrolink system consists of three main lines and a city centre spur. The original routes, now referred to as Phase 1, run from Manchester to Bury in the north and Altrincham in the south. These lines were converted from main line railway routes, and linked across the city centre by a street-running section from Victoria station to G-Mex (next to Deansgate station). There is also a spur in the city to Piccadilly main line station. These lines opened in 1992.

Following on from the success of the initial network, construction began in 1997 on the Phase 2 line through the redeveloped Salford Docks to Eccles, in the west of Manchester. This partially opened in 1999, with full service commencing in 2000.