There's no train connection with Buenos Aires Jorge Newbery Airport.
Car and bus
Aeroparque Jorge Newbery is situated only 3 kilometers from Buenos Aires' center. The airport is easily accessible from the city center by rental car via the Avenida 9 de Julio and then the Pte. Arturo Illia. Just before the airport you bear off to the left to the Avenida Rafael Obligado Costanera. After a bit more than two kilometers you reach the entrance of the airport.
A shuttle bus of the company Manuel Tienda Leon departs every half hour to Retiro train station and then on to the central bus station Madero near the Plaza San Martin. Some buses subsequently continue to Buenos Aires Ezeiza Airport.
Car rental Buenos Aires Jorge Newbery Airport
You can rent a car in the Arrivals Hall. Six car rental companies are present at Buenos Aires Jorge Newbery: Avis, Hertz, Alamo/National, Localiza, VIP Car and World Car. You can also book a car in advance using the service provided by EasyTerra; they compare the rates of several providers in a single quote.
There are taxis outside the Arrivals Hall. These are all registered taxis and can be recognized by the black-yellow color. The starting price is 4.60 pesos and subsequently 0.46 pesos per 200 meters. The total price for a taxi ride to Buenos Aires' center amounts to 20-25 pesos.
A parking garage (Parking Sur) is connected with the terminal. There's also a large parking lot (Parking Norte) on the northern side of the airport. There are no separate parking places for short or long-term parking. You pay 8 pesos per half hour.