There might be oodles of venomous snakes in Thailand, but no number of dangerous serpents could possibly take away from the sheer gorgeousness of this country. Nope, the fabled Land of Smiles will always be one of our favorites, offering glimpses of gold-glimmering Buddhist temples, the idyllic beaches of the Andaman Islands, and the misty hills around Chiang Mai. We’re very much in love.
But that doesn’t mean you shouldn’t know about the deadly snake species that occupy this corner of Southeast Asia. You most certainly should. Being aware is the first step to being prepared, so you can dodge any creatures that have the power to ruin that jaunt to sun-kissed Koh Samui or the buzzy night markets of Bangkok.
Cue this guide. It lists seven of the most venomous snakes in Thailand. Some of them are super-rare, while others are worryingly commonplace, ranging from infamous king cobras to colorful red-necked keelbacks that you really don’t want to hang around to snap photos of. Trust us!
Malayan pit viper
The Malayan pit viper is certainly one to be avoided. It’s one of the deadliest snakes in all of Asia, let alone one of the most venomous snakes in Thailand. Its global range goes from the lowland forests of Laos to the surf-washed islands of Indonesia. They are also extremely common in the Land of Smiles, particularly in coastal woodland areas and bamboo forests.
Bites from these guys are extremely dangerous. A venom is injected at the site of contact that will destroy almost any living cell that it comes into contact with. Victims will have to endure rotting flesh and necrosis, along with hematological effects such as bleeding from the eyes and nose (it really is Halloween stuff this, eh?).
You can always identify a Malayan pit viper thanks to the trademark triangular shape of the head. It’s more in line with the rattlesnakes of North America and joins with a long body that’s flatter underneath than it is on top, covered in hard-to-see camouflage patterns of browns and dusky beiges.
The monocled cobra might just be the most dangerous of all the venomous snakes in Thailand. It’s thought to be responsible for more fatalities than any other snake species in the Land of Smiles. To put that more simply: It kills more people in Thailand than any of the other serpents on this list!
How? Monocled cobras have a very strong neurotoxin venom that acts to block the proper transmission of nerve endings. That can lead to paralysis, respiratory failure, muscle spasms, and more. However, early symptoms of a bite include skin flushes and heart palpitations. Death can come within the hour if a monocled cobra bite is left untreated.
These guys are infamously adaptable. They can live in a variety of places, including open farm fields, wet rice paddies, and jungles. They’re also pretty active during the day, which isn’t good news for tourists, and are often spotted crossing roads or sunning themselves on sidewalks in Thailand, so be careful where you step!
The red-necked keelback is a real favorite among herpetologists because it’s a truly beautiful snake. They have a unique color pattern; a gradient of light-yellows on the upper neck that turns to rich oranges and then fades into a sort of fusion of greys and blacks towards the tail. They’re also delicate and small specimens, rarely measuring more than a meter.
Despite the good looks, you won’t want to get too close. They are rated as one of the most venomous snakes in Thailand thanks to a venom that can cause severe hemorrhaging of the brain and kidney failure – a double whammy of fatal effects.
The good news is that the red-necked keelback is a rear-fanged snake. That means they need to bite for a long time to inject a deadly dose of venom or will need to bite the victim on multiple occasions. In fact, a long time went by when folk thought that the red-necked keelback wasn’t dangerous at all, and people even used to keep them as pets!
White-lipped pit viper
Like all pit vipers, the white-lipped pit viper possesses a potentially deadly venom that’s capable of killing a fully grown adult human. It’s a procoagulant venom that disrupts the blood system and leads to excessive bleeding, necrosis of the flesh, and severe pain and swelling at the site of contact. The one smidgen of good news is that bites from white-lipped vipers are rarely fatal.
These guys like to stay in semi-wooded and wooded parts of the Land of Smiles. They reside between sea level and 500 meters up, and usually only come out at night. However, given their relatively aggressive nature, and the fact that they often live near towns and villages because of the constant presence of water, encounters with humans are pretty common.
You can’t exactly miss them. They are bright – as in zingy, grass-bright – green. The body twists all the way to a pointed head that has inlayed eyes that are tinged with a sort of mustard yellow. Fully grown adult members of the species typically measure no more than one meter in length. Not big; just dangerous.
The banded krait (Bungarus fasciatus) lives right across the whole of Indochina and the Indian subcontinent. However, the epicenter of its range is very much in Thailand and the greater Malay Peninsula, where this brightly colored serpent likes to inhabit dry and dusty areas like farm fields at altitudes generally lower than 2,200 meters above sea level.
They’re pretty hard to miss. The banded krait has a bold pattern of alternating black and yellow stripes, topped by an arrowhead-shaped skull that’s inset with jet-black eyes. The longest specimen ever found in this species measured 2.5 meters in all, so they can grow pretty long, however most manage just 1.5-2 meters.
When it comes to the venom, don’t get complacent. The vast majority of Asian krait species are super-dangerous. It’s no different here, as each bite can yield up to 114mg of poison, which can cause respiratory failure, vomiting, abdominal pain, and, eventually, death.
Eastern Russell’s viper
The eastern Russell’s viper is an offshoot of the more populous Russell’s viper that lives right across Asia. Also known as the Siamese viper, these guys are, without question, up there with the most venomous snakes in Thailand. They’re capable of inflicting a fatal bite that causes severe complications like sepsis, necrosis of the flesh, and total renal failure. Often, victims will die up to two weeks after being bitten.
The species possesses a very distinctive camo pattern on the back. It’s made up of alternating diamond shapes with borders of olive brown and light yellow. The upshot? They’re not at all easy to spot, especially in their preferred habitats of rice paddies and straw grasses and light woodlands.
Eastern Russell’s vipers are calm snakes until threatened, which is when they are known to become extremely aggressive. They’ll first try to deter dangers by moving their head in swift, sharp S-bends in the air. Once they attack, they usually try to sink their teeth in deep and stay in contact with the victim for some time, meaning a single bite is enough to yield a lethal venom dose of 70mg or so.
The king cobra might just be the most feared snake in all of Asia. This legendary elapid is certainly venomous enough to deserve the rep – it has a combo of neurotoxins and cytotoxins that are capable of interfering with the operation of the central nervous system and can lead to cardiac arrest and death within half an hour. It can also inject a whopping 480mg of venom in a single bite, enough to kill whole cohorts of humans, never mind just one!
King cobras can be identified by their distinctive hood. It’s a wide flap of flesh that extends out from both sides of the head. They use that in conjunction with loud hissing sounds when they feel threatened, so be sure to steer well clear if you happen to come across one in attack mode.
In Thailand, cobras are found all over the country, from the coastal forests of the south to the hills of the north. They tend to prefer wooded areas below 2,000 meters up and often live near reliable water sources. These days, king cobras are listed as Vulnerable by the IUCN, and they’re threatened by significant habitat loss in the Land of Smiles and Southeast Asia more generally.
What is the most venomous snake in Thailand?
The most venomous snake in Thailand is the monocled cobra. It’s rated as highly toxic on the LD scale and is made even more dangerous by the fact that they’re often active during the day. Special mention should also be made of the eastern Russell’s viper, which is known to administer high dosages of venom at every bite. You won’t want to encounter either of them!
How many venomous snakes are there in Thailand?
Of the hundreds of snakes that live in Thailand, around 60 are considered venomous and potentially dangerous to humans, though not all have a bite that will be fatal. Of those 60, about 50% live on land, while the other half live in water-based habitats.
Are there king cobras in Thailand?
There sure are. King cobras live all over South and Southeast Asia, spreading all the way from the Western Ghats in India to the jungles of northern Vietnam. They’re most commonly found in areas below 2,000 meters above sea level, living in thick undergrowth like bamboo woods and dense jungle. Just be careful if you’re heading out hiking in the Land of Smiles!
Are there poisonous snakes in Bangkok?
This might come as a shock, but an estimated 3,000 snakes can be reported and captured in the Thai capital in any given month. Yep, snakes are very common in Bangkok. Thankfully, most will be non-venomous, though there have been some sightings of dangerous cobras and pit vipers, with increasing reports of encounters in the last couple of years.