Commercial operation began September 14, 1974, with trains running in the first seven kilometers between Jabaquara and Vila Mariana stations.

The choice of this route was motivated by the nonexistence of alternatives for collective rail transport for the residents of Santana and Jabaquara, and also to relieve the already complicated traffic in the city's Center.

The Consortium that won the bid for the construction of the line was HMD, an association of two German companies, Hochtief and Deconsult, and the Brazilian Montreal.

This consortium applied the newest technologies available at the time, such as stainless steel cars, automatic train control and signaling system, third biometallic track, electric car traction and potent electronics, making the São Paulo Metro one of the fastest and most modern in the world.

The project was cancelled; however, about 200 metres (660 ft) of the branch were constructed and its initial stretch can still be noticed at Paraíso station.