Line M3 is a north-south connection on the Pest side of the city. Apart from the southern terminus Köbánya-Kispest, all stations are underground.

The first part (Deák tér - Nagyvárad tér) opened in 1976, and in various stages the line was extended in both directions. In 1990 it reached Újpest Központ. The line was built deep underground in the inner city between Nyugati pályaudvar and Klinikák. All other stations are sub-surface except Kőbánya-Kispest. All deep stations are of the 5-tube type except Kálvin tér, which has a special 6-tube design.

The original line was planned to run from Újpest István tér to Kispest Vörös Csillag Traktorgyár. The construction started in 1970. Until the completion of the depot at Kőbánya-Kispest, there was a small depot at the Nagyvárad tér crossover area. The escalator area at Kálvin tér for line 4 was built back in 1976, although at that time line 4 was supposed to be built belwo line 3. Line 4 has now been built above line 3 but the old escalator shaft was still used. Határ út station was built with 3 tracks because according to the plans it was to become a junction for the planned branch to the airport. Later the southern terminus was shifted from Határ út to Kőbánya-Kispest and the northern terminus was fixed at Káposztásmegyer. This line would have been 20.5 km long. From Rákospalota-Újpest train station the line would have been on the surface. A second depot was planned at Káposztásmegyer, a street there already makes reference to this (Járműtelep utca). After Újpest-Központ the tunnel was actually built up to the next station, including the signs. For the Káposztásmegyer section Hungarian trains were to be built, but only a prototype was manufactured.

In 1990 the whole line was upgraded for half-automated operation (ATO). The driver has to close the doors and push the start buttons only. Between Nov 2017 and May 2023, line M3 was upgraded again, with several partial closures and all stations modernised - for more details click here!

Underground section: 15.5 km
Average station distance: 866,3 m
Shortest station distance: 469 m
Longest station distance: 1753 m
Platform lengt: 120 m
Deepest station: Kálvin tér - 28.24 m

31-12-1976: Deák Ferenc tér - Nagyvárad tér
20-04-1980: Nagyvárad tér - Kőbánya-Kispest
30-12-1981: Deák Ferenc tér - Lehel tér
07-11-1984: Lehel tér - Árpád híd (now Göncz Árpád városközpont)
14-12-1990: Árpád híd (now Göncz Árpád városközpont) - Újpest-Központ

Újpest-Központ

Tram

Újpest-Városkapu

Gyöngyösi utca

Forgách utca

Göncz Árpád városközpont

(until 2019: Árpád híd)

Tram

Dózsa György út

Lehel tér

Tram

Nyugati Pályaudvar

Tram

Arany János utca

Deák Ferenc tér

Line M1 | Line M3 | Tram

Ferenciek tere

Kálvin tér

Line M4

Tram

Corvin-negyed

Tram

Semmelweis Klinikák

Nagyvárad tér

Népliget

Tram

Ecseri út

Tram

Pöttyös utca

Határ út

Tram

Kőbánya-Kispest