The service is currently operated by the state-owned company Operadora Ferroviaria Sociedad del Estado after the Government of Argentina rescinded its contract with Corredores Ferroviarios in March 2015.

The first line was built and operated by the Buenos Aires Northern Railway, a British-owned company that ran trains from Central Station (then from Retiro) to Tigre, joining both cities in 1857.

[1] The lack of maintenance of the FIAT 7131 coaches meant that some of them went out of service, so in 1987 Ferrocarriles Argentinos acquired new light railcars for the Zárate and Capilla del Señor branches.

The company bought 8 units made by Materfer which were soon nicknamed Pitufos (a Spanish translation for "Smurfs" due to their small size).

After the Government of Carlos Menem privatised the urban railways services private company Trenes de Buenos Aires (TBA) took over the Mitre Line.

These coaches were built by local factory Emprendimientos Ferroviarios S.A. (EMFER) and featured air conditioning, ABS brakes and computer-supervising systems.

The future investments included acquiring 492 brand-new electric multiple units, the refurbishing of more than 100 km of existing tracks, and the installation of new signalling, among other improvements.

Nevertheless, the Government of Fernando De la Rúa (which had come to power in 1999) made changes to the original project, reducing the amount of the budget to US$1.3 billion.

The State granted subsidies to TBA (and the rest of the private operators) as a way to compensate for the losses arising from the change in plans and to avoid fare increases.