|Service type||Commuter rail|
|Locale||Buenos Aires Province|
|Current operator(s)||Trenes Argentinos|
|Ridership||10,5 million (2013)|
|Website||Ministry of Transport|
|Distance travelled||174 km|
|Average journey time|
|Track gauge||1,676 mm (5 ft 6 in)|
|Track owner(s)||Government of Argentina|
This line had previously been run by the state-owned company Ferrocarriles Argentinos since nationalisation of the Argentine railways in 1948. FA operated the trains until 1991 when residual company FEMESA temporarily took over all the urban services prior to be privatized. After the Government of Carlos Menem privatized the urban railways services private company Trenes de Buenos Aires (TBA) took over Mitre Line.
TBA operated the line until the 2012 Once station rail disaster happened. As a result, the National Government revoked the concession granted to TBA and gave the Mitre and Sarmiento to UGOMS, that operated the line until 2014 when it was re-privatised and given under concession to "Corredores Ferroviarios S.A."  
In 2014 the Government announced the acquisition of new coaches to increase the Mitre Line rolling stock. The coaches were manufactured by Chinese company CSR Corporation Limited, the first to arrive in June 2014.
The performance of the Sarmiento line will be greatly improved by drilling a new tunnel. Under plans announced in 2006, a 33 km tunnel is to be bored between Moreno and Caballito in order to replace the surface alignment of the Sarmiento commuter route. According to the Minister of the Interior and Transport, the first stage will cost 11·5bn pesos, removing many level crossings which would ‘avoid many accidents and much loss of life’. The new underground alignment should increase the service frequency to every 3 min, increasing capacity from 100 million to 280 million passenger-journeys a year. The tunnel segment will have 13 underground stations. Drilling started 2 July 2012. During the construction, service on the surface line will continue.
- "Sin controles, se desplomó la venta de boletos en los trenes", La Nación, 14 Jan 2014
- "El gobierno nacional estatizó los ferrocarriles Sarmiento y Mitre", Infobae, 11 Sep 2012
- "Trenes: le dan a Roggio el Mitre y el San Martín y a Emepa, el Roca y el Belgrano Sur", La Nación, 12 Feb 2014
- "Las privadas volverán a operar la mayoría de las líneas ferroviarias", Clarín, 12 Feb 2014
- "El Gobierno estableció un nuevo régimen de operaciones de las líneas ferroviarias", Telam, 12 Feb 2014
- "CSR fleet enters service in Buenos Aires", Railway Gazette International, 10 June 2013
- "Ya está en viaje la primera de las 25 formaciones para la línea Sarmiento", Telam, 7 Jan 2014
- "Ceremony marks start of Sarmiento tunnelling". Railway Gazette. 2012. Retrieved 2012-07-05.
- Sarmiento Line at Ministry of Transport of Argentina
- Tren Sarmiento Line website
- Trenes Argentinos website
- Mitre-Sarmiento website (Archive)
|Wikimedia Commons has media related to Sarmiento Line.|