[2] The 2 Line is the second oldest in the network, identified by the color blue and runs from West to East and then North to South, turning at the city center.

It is linked with the Mexico City Light Rail to Xochimilco at the Tasqueña terminal.

This line was temporarily served by an NM-02 train printed with landscapes and images of Mexico City.

Cuatro Caminos would remain as the only station to serve the suburbs of Mexico City until 1991, when Line A opened and service reached the municipality of Los Reyes La Paz, in the southeastern part of the State of Mexico with the stations Los Reyes and La Paz.

This line has seen the worst accident in Mexico City history when on October 20, 1975, when there was a crash between two trains at Viaducto metro station.