The 7 Most Dangerous Snakes in Argentina (Venomous Snakes)

dangerous snakes in Argentina

When you think of Argentina what comes to mind? Salsa? Probably. Soccer? More than likely. Snakes? Perhaps not, but you might be surprised at just how dangerous the snakes in Argentina can be. There are plenty of them too, with over 130 species of snake known to live in Argentina.

Of the many species of snakes that can be found in Argentina, 18 are known to be venomous. The majority of these (and by far the most dangerous) are pit vipers, though there are coral snakes, constrictors and rattlesnakes in Argentina that also carry plenty of threat. If left untreated a bite from any of the many venomous snakes in Argentina are capable of proving fatal.

Argentina’s snakes are found throughout the country, especially the near-ubiquitous vipers. Thankfully snakebites are rare and are easily treatable with highly effective antivenins. All the same, here are seven of the most dangerous snakes in Argentina you might want to keep an eye out for.

Bothrops jararacussu

Bothrops jararacussu
Photo by Wikimedia Commons

The most deadly of the snakes in Argentina belong to a classification of vipers called Bothrops. The term comes from Latin, meaning ‘pit’, which explains why Bothrops are more commonly known as pit vipers. Bothrops vipers are the most deadly snakes in North and South America, to blame for more fatal attacks on humans in the Western Hemisphere than any other type of snake. The Bothrops jararacussu, found across a wide range of South America, is one of the most deadly pit vipers of them all.

Growing up to two meters long, the jaracussu lives mostly in the forests of northeast Argentina. Amongst all of the deadly vipers in Argentina the jararacussu is possibly the most feared as the venom it produces is as powerful as it is lethal.

The jararacussu injects its venom with a bite, passing the venom through its long sharp fangs. That venom contains a devastating concoction of potentially deadly toxins that can cause necrosis, cerebral hemorrhage, shock, kidney failure, respiratory failure, and ultimately death. If bitten by a jararacussu a victim will need urgent medical care and will need to be treated with anti-venom as quickly as possible.

Bothrops alternatus

Bothrops alternatus
Photo by Wikimedia Commons

The Bothrops alternatus, also known as the crossed pit viper, are similar in size to the jararacussu, and though it’s highly venomous it isn’t thought to be as deadly. Also found across a large swathe of South America, the crossed pit viper is known to inhabit the Sierra de la Ventana mountain range in Buenos Aires Province.

Believed to be capable of growing to around two meters in length a bite from the crossed pit viper can do a fair amount of damage. And even though its venom isn’t as strong as that of the jararacussu, there have been occasions when bites from crossed pit vipers have proved to be fatal.

Ultimately, if you can avoid getting bitten by a crossed pit viper it’s for the best. After being bitten, localized pain in the area will only get worse and will be accompanied by swelling. Bleeding gums are a common symptom of a crossed pit viper bite as is severe tissue damage to the bitten area. Some bite victims have also experienced blistering, whilst some also suffer from necrosis. Untreated bites have even lead to gangrene and there have been some cases that have required limb amputation.

Patagonian lancehead

Photo by Wikimedia Commons

The Patagonian lancehead is another viper and, as its name suggests, is only found in Argentina. Known to inhabit several regions throughout the country, the Patagonian lancehead’s habitat stretches as far south as the 47th south parallel, which makes it the world’s most southerly snake. The Patagonian lancehead can survive in a wide range of environments, from dry savannahs to coastal dunes and riverbanks.

Though little is known about the strength of the Patagonian lancehead’s venom research has shown it to be potentially deadly. Whilst they’re not the largest snake in Argentina, growing to a length of only around 60 to 80 centimeters, the Patagonian lancehead are nocturnal and very territorial. They’re also very defensive and have an irritable temperament with a very short fuse, which is not an ideal combination if you happen to disrupt one in the wild.

If bitten by a Patagonian lancehead you can expect to suffer from symptoms such as internal bleeding and damaged tissue around the wound.

South American rattlesnake

South American rattlesnake
Photo by Wikimedia Commons

The South American rattlesnake is another of Argentina’s highly venomous pit vipers. Though generally non-aggressive and likely to back away from humans, if it feels threatened the South American rattlesnake won’t be afraid to defend itself.

Found mostly in Argentina’s northern provinces, the South American rattlesnake carries a potentially fatal venom. Along with the Bothrops jararacussu the South American rattlesnake is not only one of the most deadly snakes in Argentina, but amongst the most dangerous animals in the country too.

An untreated bite from a South American rattlesnake is almost certain to lead to death. The venom attacks the nervous system, causing a bite victim to experience any number of horrific symptoms, including spontaneous bleeding, paralysis, permanent blindness, respiratory failure, and kidney failure.

Kidney failure is often the most common ultimate cause of death in those who have lost their lives following a South American rattlesnake bite. Researchers believe that a dose of just 18 milligrams of the South American rattlesnake’s venom is enough to kill an adult, with each snake carrying around 100 milligrams of venom.

Yellow anaconda

Yellow anaconda
Image by SeaReeds from Pixabay

The yellow anaconda is another snake that lives throughout South America, and is also known as the Paraguayan anaconda. In Argentina, the yellow anaconda can mostly be found in the northeastern region, where it lives in damp areas near marshes and swamps. The yellow anaconda is one of the largest snakes in the world, with adults growing anywhere between three and four meters in length. Solitary by nature, the yellow anaconda only mixes with other snakes during the breeding season.

Known to be fairly timid, the yellow anaconda is also unpredictable and will attack aggressively if it feels as though it is in danger. Unlike the other snakes on our list, the yellow anaconda is non-venomous, but kills its prey through constriction.

The yellow anaconda lives off a varied diet of birds, reptiles and mammals that it traps and slowly suffocates. Some anacondas have been known to catch and kill larger mammals such as capybara and deer. While attacks on people are rare, being able to capture larger animals means that the yellow anaconda is a threat to humans, particularly to small children.

Neuwied’s lancehead

Neuwied's lancehead
Photo by Wikimedia Commons

The Neuwied’s lancehead is another of Argentina’s many pit vipers that are also common throughout much of South America. Capable of living in a range of environments it’s also common throughout Argentina too, found in most of the country outside the southern provinces. Though relatively small compared with the other vipers on our list, usually growing to around sixty centimeters in length, the Neuwied’s lancehead is responsible for most of the snakebites in Argentina.

Like all pit vipers, the Neuwied’s lancehead carries a particularly nasty venom that can lead to some nasty repercussions. As well as severe pain around the wound, a bite will often be followed by extreme swelling and severe bruising. Necrosis is another common symptom, which causes death in the cells of affected tissue, as is coagulopathy, which prevents the victim’s blood from clotting, leading to uncontrolled bleeding.

Thankfully, due to the many bites from Neuwied’s lanceheads in Argentina, several antivenins exist and with quick and effective treatment a bite victim should be expected to make a full recovery.

Brazilian lancehead

Brazilian lancehead
Photo by Wikimedia Commons

The last on our list of deadly snakes in Argentina, the Brazilian lancehead is another venomous viper. Though much more common in Brazil (hence the name) these snakes have also made their way over the border and into Argentina. Largely nocturnal and terrestrial, the Brazilian lancehead typically grows to around two meters in length.

Though their diet consists mostly of relatively easy prey such as rodents and birds, the Brazilian lancehead can be vicious. Incredibly aggressive and prone to attack, the Brazilian lancehead is capable of leaping vertically toward its victims and reaching a great height, often as high as the upper body when attacking a human.

Besides their short fuse and unpredictable temperament, the Brazilian lancehead also packs a deadly venom. All bites from a Brazilian lancehead should be treated urgently and considered to be potentially lethal as their venom can lead to a whole host of conditions, including intense pain, localized swelling, and muscular necrosis.

In some cases, victims have had to have limbs amputated following the severe damage caused by a bite from a Brazilian lancehead. The venom can also eventually lead to hemorrhaging and uncontrolled bleeding. Some victims have also suffered from a stroke following a bite from a Brazilian lancehead.

What is the most dangerous snake in Argentina?

The most dangerous snake in Argentina is the Bothrops jararacussu due to the severity of its venom. Of all the vipers in Argentina, the Bothrops jararacussu carries the most deadly venom. The South American rattlesnake is a close second and also incredibly dangerous.

Are there any venomous snakes in Argentina?

Yes, there are 18 different species of venomous snake in Argentina, most of which are pit vipers.

Are snakes common in Argentina?

Snakes are common in Argentina, and are found throughout the country especially in the northern provinces. Vipers are particularly common with the Patagonian lancehead believed to be the most southerly snake in the world.


For more than 11 years, Joe has worked as a freelance travel writer. His writing and explorations have brought him to various locations, including the colonial towns of Mexico, the bustling chowks of Mumbai, and the majestic Southern Alps of New Zealand. When he's not crafting his next epic blog post on the top Greek islands or French ski resorts, he can often be found engaging in his top two hobbies of surfing and hiking.

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