Malaria still exists in Thailand, but almost only in rural forest along the borders with Myanmar, Cambodia, Laos and Malaysia. Bangkok, Chiang Mai, Pattaya and the main tourist islands carry no or very low risk, so most visitors do not need malaria tablets. What everyone should remember is the follow-up rule: a fever within a year of the trip needs a malaria test.
Malaria is a parasite infection spread by mosquitoes that mostly bite between dusk and dawn. Thailand has spent decades pushing it back, and the cases that remain cluster in forested border districts where few tourists go. The UK and US health agencies agree on that picture, but they draw the lines in slightly different places and give different advice on tablets for the border areas. This page sets out both, so you and a travel clinic can decide for your own route.
Malaria in Thailand: the official picture (checked October 2026)
- No risk (UK)
- The cities of Bangkok, Chiang Mai, Chiang Rai, Koh Phangan, Koh Samui and Pattaya
- No transmission (US CDC)
- The Krabi islands (Koh Lanta, Koh Phi Phi, Koh Yao Noi, Koh Yao Yai) and Pattaya City
- Main risk
- Rural forest and forest fringe in provinces on the Myanmar, Cambodia and Malaysia borders (CDC); forested borders with Cambodia, Laos and Myanmar (UK)
- Tablets
- UK: not advised for ordinary travelers anywhere in Thailand. CDC: advised only for the border provinces named above
- Main parasite
- P. vivax about 80 % of cases, P. falciparum under 20 % (CDC)
- After the trip
- Fever up to one year later: see a doctor at once and mention Thailand
Where the risk is: forested borders, not resorts
The UK Health Security Agency, through its TravelHealthPro service, splits Thailand into three tiers. There is a low risk in the rural, forested border areas with Cambodia, Laos and Myanmar. There is a very low risk in the rest of the country, which it says includes Kanchanaburi and the Bridge over the River Kwai. And there is no risk in the cities of Bangkok, Chiang Mai, Chiang Rai, Koh Phangan, Koh Samui and Pattaya. Bite avoidance is advised in all three tiers.
The US CDC says transmission happens mainly in provinces bordering Myanmar, Cambodia and Malaysia, especially in rural forest and forest-fringe areas, with rare cases in Buri Ram. It reports rare to few cases in Bangkok, Chiang Mai, Chiang Rai, Koh Pha Ngan, Koh Samui and Phuket, and no transmission at all on the Krabi islands or in Pattaya City.
Two details matter for beach travelers. Phuket is not on the UK's "no risk" list; it falls into the very low tier, and the CDC lists it among places with rare cases. And no agency says the whole south is malaria-free. The honest summary for the beaches is "very low risk", which is why bite avoidance still makes sense there.
Tak and the Myanmar border: where Thailand's cases cluster
Thailand runs a national malaria elimination programme under the Department of Disease Control (DDC), whose Division of Vector-Borne Diseases tracks cases by village. Tak province, on the Myanmar border, is where much of that effort now goes: in April 2024 the Bangkok Post reported, citing the DDC, that over half of the cases detected that year were in Tak, and in October 2026 the DDC's vector-borne disease division was working in the province on case management.
We could not get a reliable national case total for 2025 or 2026: the DDC's public dashboard showed only that its weekly data was being updated when we checked. Rather than print an old or partial number, we point you to the DDC's malaria information system (linked under Sources) for the latest figures.
For travelers, the practical meaning is simple. Trekking, camping or volunteering in forest near the western border, for example around Tak, Mae Hong Son or the far side of Kanchanaburi towards Sangkhlaburi, is a different risk from a city break. A night in a national park campsite deep in border forest is where the advice in the next section applies; our guide to camping in Thai national parks covers the practical side of those trips.
Do you need malaria tablets? UK and US advice differ
This is the point where the two agencies part ways, and neither is wrong: they weigh a very low risk differently.
| Where you go | UK (TravelHealthPro) | US (CDC) |
|---|---|---|
| Bangkok, Chiang Mai, Pattaya, Samui, Phangan | No risk; no tablets | No tablets; bite avoidance |
| Phuket and the rest of the country | Very low risk; tablets not advised | No tablets; bite avoidance |
| Rural forest on the Myanmar, Cambodia or Laos border | Low risk; tablets only in exceptional cases | Tablets advised in provinces bordering Myanmar and Cambodia (not Buri Ram); the Laos border is not on its tablet list |
| Provinces bordering Malaysia | Very low risk; tablets not advised | Tablets advised |
The UK's "exceptional circumstances" are travelers to the low-risk border forests who are at higher risk of catching malaria, such as long-term travelers visiting friends and relatives, or at higher risk of severe illness: people over 70, people with a weakened immune system or several serious conditions, pregnant women, infants and young children. The UK also says people with no spleen, or one that works poorly, should be dissuaded from traveling to any malaria-risk area.
Which tablet, if any, is a decision for a travel clinic or doctor who knows your health and your route. The CDC notes that malaria in Thailand is resistant to chloroquine and mefloquine, so a leftover pack from an earlier trip elsewhere may be the wrong medicine. If you are prescribed tablets, the CDC says to keep taking them after you get home for as long as the prescription says. Our guide to vaccinations for Thailand covers the rest of that pre-trip appointment.
Tell the clinic your exact provinces, not just "Thailand". The advice for a week in Bangkok and Krabi is completely different from a jungle trek near the Myanmar border, and the same clinic may give opposite answers to the two trips. Bring a rough itinerary with town names.
Avoiding bites from dusk to dawn
The UK calls this the B in its "ABCD" of malaria prevention: Awareness of risk, Bite prevention, Chemoprophylaxis (tablets) where appropriate, and quick Diagnosis. The mosquitoes that carry malaria feed mainly between dusk and dawn, which is the opposite of the daytime mosquitoes that spread dengue, so in border forest you need protection around the clock. Repellent on exposed skin, long sleeves and trousers in the evening, and a screened or air-conditioned room or a net are the core habits; our article with 23 tips for avoiding mosquito bites goes through repellents and room choice in detail.
Dengue is the mosquito illness most visitors to Thailand actually meet, in cities and on the islands; it has its own page on dengue fever, its warning signs and testing. The two other daytime-mosquito viruses are covered in our guide to chikungunya and Zika.
The symptoms to act on, even months later
The UK lists these as the usual early symptoms of malaria:
- a fever of 38 °C (100 °F) or more
- feeling cold and shivery
- headache, aching muscles
- nausea and vomiting
The early signs look like flu, which is why malaria is easy to dismiss. Symptoms can start anywhere from eight days to one year after the infective bite, and the UK warns that people with malaria can get worse quickly.
A fever within a year of a trip to a malaria area needs a same-day doctor. The UK says a fever of 38 °C or more starting more than a week after being in a risk area, or any symptoms that could be malaria within a year of coming home, need immediate medical care. The CDC gives the same one-year window. Tell the doctor you were in Thailand and which provinces; malaria is diagnosed with a blood test, not by symptoms alone.
A fever after forest trekking can also be something other than malaria. Scrub typhus, for example, is caught in rural grass and scrub, and our page on scrub typhus explains its signs. That is exactly why you should not guess: let the doctor test.
Getting tested and treated in Thailand
If you fall ill while still in Thailand, go to a hospital rather than a pharmacy. Public hospitals can test for malaria, and private hospitals in the cities run their own emergency departments; our guide to hospitals in Thailand explains how the two differ and how payment works. For someone who is seriously ill, call 1669 for an ambulance.
We found no official source saying that foreign visitors get malaria testing or treatment without charge, so plan for it to be billed like any other care. Check that your travel insurance covers hospital treatment before you go into remote areas, and keep receipts and the test result.
The UK counts pregnant women among those at higher risk of severe malaria; our page on traveling to Thailand while pregnant covers that case.
Frequently asked questions
Is there malaria in Bangkok?
The UK says there is no risk of malaria in the city of Bangkok, and the CDC reports only rare to few cases there and recommends no tablets. Visitors to Bangkok should still avoid mosquito bites, mainly because of dengue.
Do I need malaria tablets for Phuket or Koh Samui?
No, according to both the UK and the CDC. The UK lists Koh Samui as no risk and Phuket as very low risk, with tablets not advised; the CDC reports rare cases on both islands and recommends bite avoidance only.
Do I need malaria tablets for Chiang Mai or Kanchanaburi?
For Chiang Mai, neither agency advises tablets. Kanchanaburi borders Myanmar, so the CDC's border-province rule technically covers it, while the UK calls Kanchanaburi and the River Kwai area very low risk with no tablets. Ask a travel clinic, giving your exact plans.
How long after Thailand can malaria symptoms appear?
The UK says between eight days and one year after the infective bite. Any fever in that year, especially after time in border forest, should be checked by a doctor straight away, and you should mention the trip.
Is malaria treatment free in Thailand?
We found no source saying it is free for tourists. Public and private hospitals can test and treat malaria, but expect to pay or claim on your travel insurance, as for other hospital care.
Sources
- UKHSA TravelHealthPro – Thailand: malaria risk, antimalarials and symptoms (checked October 2026)
- CDC – Thailand traveler view: malaria (table updated 23 April 2025) (checked October 2026)
- Department of Disease Control – Thailand Malaria Elimination Program, MIS Online (in Thai) (checked October 2026)
- DDC Division of Vector-Borne Diseases – Malaria case management visit to Tak, 26 October 2026 (in Thai) (checked October 2026)
- Bangkok Post – Alert sounds over rise in malaria cases (26 April 2024) (checked October 2026)