Argentina shares land borders with five neighboring countries: Chile, Bolivia, Paraguay, Brazil, and Uruguay. Together these frontiers stretch for roughly 11,968 km, ranking among the longest combined land borders in South America. As the continent's second-largest nation, Argentina occupies the southeastern flank of South America, with its neighbors wrapping around its northern and western edges while the Atlantic Ocean forms its long eastern coastline.
Chile: The Longest Andean Frontier
Chile is Argentina's longest neighbor, sharing a border of about 5,308 km that runs almost the entire length of both countries from the high deserts of the north to the windswept islands of Tierra del Fuego in the far south. This is one of the longest international boundaries in the world, and for most of its length it follows the crest of the Andes mountain range, where peaks act as a natural watershed dividing the two nations. The boundary includes Aconcagua's surroundings, the Patagonian ice fields, and the dramatic glaciers near El Calafate. Mountain passes such as the Cristo Redentor tunnel near Mendoza carry vital road and trade traffic between Buenos Aires and Santiago.
Bolivia and Paraguay: The Northern Neighbors
To the north, Argentina meets Bolivia along a border of roughly 942 km. This frontier crosses the high-altitude Puna plateau and the subtropical lowlands of the Gran Chaco, linking Argentine provinces like Jujuy and Salta with Bolivian departments rich in shared Andean culture, language, and cross-border labor migration.
Paraguay lies to the north as well, sharing about 2,531 km of border largely defined by rivers. The Pilcomayo, Paraguay, and Paraná rivers trace much of this boundary, making waterways central to trade and transport between the two landlocked-leaning interior regions. The Argentine province of Formosa and the city of Clorinda sit directly across from Paraguay's capital region.
Brazil and Uruguay: The Northeastern Edge
Brazil, the largest country in South America, shares a comparatively short 1,263 km border with Argentina in the northeast, concentrated in the province of Misiones. This region is home to the spectacular Iguazú Falls, a UNESCO World Heritage Site straddling the Iguazú River where Argentina, Brazil, and Paraguay nearly meet at the famous Triple Frontier. The falls draw millions of visitors annually and symbolize the natural wealth of this corner of the continent.
Uruguay shares about 580 km of border with Argentina, much of it running along the Uruguay River. The two nations are deeply intertwined culturally and economically, sharing the Río de la Plata estuary, the tango tradition, and a love of yerba mate. Ferries cross the river daily between Buenos Aires and Uruguayan cities like Colonia del Sacramento and Montevideo, underscoring how close these neighbors remain in everyday life.
Maritime Neighbors and Disputed Waters
Beyond its land borders, Argentina faces several maritime neighbors across the South Atlantic. The Falkland Islands (Islas Malvinas), administered by the United Kingdom but claimed by Argentina, lie a few hundred kilometers off the Patagonian coast and remain a sensitive sovereignty issue. Argentina also asserts a claim over a sector of Antarctica to the far south. Its long Atlantic coastline gives the country an extensive maritime zone rich in fisheries and potential offshore energy resources.
Why Argentina's Borders Matter
Argentina's frontiers have been shaped by centuries of colonial division, independence-era treaties, and 19th- and 20th-century boundary negotiations, particularly with Chile over the Andes and Patagonia. Today these borders are far more than lines on a map. They define trade corridors through MERCOSUR, the regional bloc Argentina co-founded with Brazil, Paraguay, and Uruguay, and they shape the cultural exchange that flows across rivers and mountain passes. The diversity of terrain along these boundaries, from Andean peaks to subtropical rainforest to river deltas, reflects the remarkable geographic range of Argentina itself. To explore more about the country behind these borders, see the argentina country guide.
Frequently Asked Questions
How many countries border Argentina?
Argentina borders five countries: Chile, Bolivia, Paraguay, Brazil, and Uruguay. Of these, Chile shares by far the longest boundary, running along the Andes for more than 5,000 km.
Which country shares the longest border with Argentina?
Chile shares the longest border with Argentina at approximately 5,308 km. It follows the spine of the Andes mountains almost from the tropical north all the way down to Tierra del Fuego in the south.
Does Argentina border Brazil?
Yes. Argentina and Brazil share a border of about 1,263 km in the northeastern province of Misiones, where the famous Iguazú Falls are located near the Triple Frontier with Paraguay.
What is Argentina's total land border length?
Argentina's total land border measures roughly 11,968 km across its five neighbors, making it one of the most extensively bordered countries in South America.
