Buenos Aires, the capital of Argentina, is one of South America's biggest cities with 3 million inhabitants (Ciudad Autónoma de Buenos Aires) and 12 million in the larger metropolitan area (Gran Buenos Aires). For a city of this size the metro network is still very small although it's by far the oldest subway in South America.

After losing many passengers during the 1980's, the Subte was privatised and is now operated by Metrovías which immediately started refurbishing stations and buying new rolling stock to replace older trains, some of which have been running since the Subte opened.

The total network is approx. 48.3 km (2008) and totally underground.