Eating safely in Thailand

Thailand is one of the easiest places in Asia to eat well, from night markets to beach grills. Most stomach trouble comes from a few things that are specific to the country: tap water whose quality depends on the building, ice of unknown origin, outdoor stalls without running water, a handful of raw dishes, and seasons that change the risk. Here is what Thai and international health bodies say about each.

Can you drink the tap water in Thailand?

The answer depends on where the water comes from and what happens to it on the way.

• Bangkok and its suburbs. The Metropolitan Waterworks Authority (MWA) supplies Bangkok, Nonthaburi and Samut Prakan. In June 2025, Thailand’s Department of Health certified its tap water as drinkable, after two rounds of samples from 217 sites, from the plants to users’ premises, met its criteria.
• The catch is the building. The MWA itself asks residents to look after their pipes and storage tanks so that the water stays as clean as it was when it left the plant. As a visitor, you can’t check a hotel’s tank or a condo’s pipes.
• What health agencies tell travelers. The CDC Yellow Book says travelers should not drink tap water in Thailand and notes that bottled and filtered water are widely available. TravelHealthPro advises water that is boiled, filtered or bottled.

So, even in Bangkok, drink sealed bottled or filtered water, and use it to brush your teeth. Our guide to tap water and ice when traveling explains boiling and filters, and our page on Patong explains why tap water runs short on Phuket in the dry season.

Is the ice safe?

Ice is where Thai and international advice differ most. The CDC Yellow Book tells travelers to Thailand to avoid ice. Thailand’s Department of Disease Control tells residents to choose drinking water and ice that are clean and carry the อย. mark of the Thai Food and Drug Administration.

That mark is printed on a sealed bag, not on the ice in your glass. Following the CDC, the safer choice is to order drinks without ice unless you can see it came from a sealed, labeled bag.

Street food: what Thai health officials advise

The CDC Yellow Book calls Thailand’s street food convenient, delicious and inexpensive, and also a common source of travelers’ diarrhea: outdoor eateries often lack clean running water, which makes good hand and food hygiene hard. It advises choosing vendors who cook to order and avoiding raw foods.

Thai health officials have their own short rules, repeated in the hot season:

• “Suk, ron, sa-at”: cooked, hot, clean. Eat food that is cooked all the way through and still hot.
• “Eat hot, use a serving spoon, wash your hands.” Shared dishes come with a serving spoon; wash your hands with soap before touching food.
• Watch blanched seafood. The Songkhla office of the Department of Disease Control singles out blanched cockles, squid and shrimp, which may not be fully cooked.
• Two hours. Food kept for more than 2 hours should be reheated before eating. Trays of curries that have stood in the heat since morning are a worse bet than a wok in front of you.

Hygiene signs. France’s foreign ministry notes that hygiene in Thai restaurants is generally satisfactory, but that there is no systematic health inspection of them. The Department of Health’s current food hygiene certificates are called SAN and, for the higher level, SAN Plus. They were developed from the older Clean Food Good Taste standard. Vendors and their staff must first complete training, then local officials assess and certify the stall or restaurant; Bangkok’s Soi Ari 1 market was the first street-food market to receive SAN Plus, in July 2024. A sign is a good sign, not a guarantee.

On the map, safeat shows restaurants where our review found no food-safety concern in the last 12 months. It is a starting point for choosing where to eat, not an inspection or a guarantee, so the habits above still apply. More on stalls in is street food safe?

Raw and fermented dishes

A few Thai dishes are eaten raw or fermented, and their risks are not those of ordinary food poisoning. Raw freshwater fish, as in the koi pla of the northeast, can carry the liver fluke Opisthorchis viverrini, linked to bile duct cancer, and the CDC warns that lightly salted or pickled fish can carry it too; raw or undercooked pork can transmit Streptococcus suis, which caused 647 cases and 41 deaths in Thailand between 1 January and 8 July 2026, according to the Department of Disease Control. Which dishes are raw, what they can carry and how to order them cooked: our guide to raw and fermented dishes in Thailand.

Horseshoe crab eggs: cooking does not help

Horseshoe crab and its eggs are eaten in Thailand, and one of the two species found there, the round-tailed horseshoe crab (maeng da thuai), is poisonous in both meat and eggs, and its toxin resists heat. The Department of Disease Control recorded 6 poisoning events between 2018 and 2022, in which 18 people fell ill and 5 died, mostly in February. Symptoms can start within 30 minutes with numbness around the mouth. Telling the two species apart takes expertise, so the safest choice is not to eat it.

Homemade alcohol and methanol

In August 2024, at least 6 people died in Bangkok after drinking homemade alcohol, and samples from the 18 stalls that sold it contained dangerous amounts of methanol, reports the Swiss Expert Committee for Travel Medicine. Its advice: don’t drink alcoholic drinks whose origin and composition are unclear.

Seasons that change the risk

Thailand has three seasons: hot from mid-February to mid-May, rainy from mid-May to mid-October, and cooler from mid-October to mid-February. The south keeps getting heavy rain until December. On Koh Samui and in the southeast, on the Gulf of Thailand side, the rainy season usually runs from November to March (UK FCDO). Our pages on Ko Tao and Koh Phangan explain what this means for boats, water and medical help on an island.

• Hot season. The Department of Disease Control warns that hot weather makes food spoil faster. Be strictest about the two-hour rule and food left in the sun.
• Rainy season: wild mushrooms. Mushrooms that grow wild in the rains are picked and sold, and some are poisonous. The Department of Disease Control warns that folk tests do not work, that some mushroom toxins are not destroyed by cooking, and repeats its rule: “if you don’t know it or aren’t sure, don’t pick it, don’t eat it”. Skip dishes made with wild mushrooms you can’t identify, and see a doctor right away if you are sick after eating them.
• Rainy season: floods and soil. Leptospirosis occurs mainly in the south and northeast, and melioidosis is highly endemic in the northeast, with most cases from July to October (CDC Yellow Book). Between 1 January and 8 July 2026, the Department of Disease Control counted 2,002 leptospirosis cases and 1,513 melioidosis cases. It advises drinking boiled water, not wading barefoot, and keeping wounds away from soil and floodwater.

Vaccines for food- and water-borne diseases

• Hepatitis A: recommended by the CDC for unvaccinated travelers aged one year or older, and by TravelHealthPro for all previously unvaccinated travelers.
• Typhoid: the CDC recommends it for most travelers, especially those visiting friends or relatives or going to smaller cities or rural areas. TravelHealthPro is more selective and suggests it for travelers whose activities put them at higher risk. Ask a travel clinic; the vaccine is not 100% effective either way.
• Cholera: there is no active cholera transmission in Thailand and the vaccine is not recommended (CDC).

Food allergies

Food from stalls and small restaurants comes without written allergen information, so you have to ask, usually across a language barrier. The Thai word for “allergic” is แพ้ (phae). Carry an allergy card written in Thai that names every food you react to, show it each time you order, and ask about sauces, pastes and garnishes as well as the main ingredients. Our guide to eating out with a food allergy covers cards and cross-contact.

If you get sick in Thailand

• At the pharmacy, ask for ORS. Electrolyte sachets in Thailand come in two kinds. ORS (oral rehydration salts) is made for diarrhea; ORT drinks are made for exercise and heat, contain more sugar, and Ramathibodi Hospital advises against them for diarrhea, as they can make it worse. Dissolve a sachet in 150 to 250 ml of boiled and cooled or freshly opened bottled water (or as the label says), sip it through the day, and throw away what is left after 24 hours.
• Antibiotics. The CDC Yellow Book warns that gut bacteria resistant to fluoroquinolones (such as ciprofloxacin) are widespread in Thailand, and the UK FCDO warns that taking medicines without medical advice can have serious consequences and that medicines sold on the street may not be genuine. See a doctor rather than buying antibiotics on your own.
• Care. Health care in Thailand is generally of good quality and less costly than in many high-income countries, but more limited in rural areas (CDC Yellow Book). Private hospitals are of a high standard but can be expensive, and all hospitals require a guarantee of payment before treating patients (UK FCDO): keep your insurance details with you.
• Numbers. 1669 for an ambulance, 191 for the police (CDC); 1155 for the Tourist Police, a 24-hour hotline that helps visitors in several languages (Tourism Authority of Thailand); 1422, the Department of Disease Control hotline for questions about food poisoning.

When to see a doctor, with precise warning signs: food poisoning while traveling.

Official alerts

As of October 2026, the CDC Travelers’ Health page for Thailand carries an alert that Thailand is reporting increased cases of leptospirosis, which can spread through floodwater and through water or food contaminated with animal urine (see the rainy season above), and a global measles notice. TravelHealthPro’s outbreak list for Thailand covers mpox (latest July 2026), Zika (July 2026), chikungunya and dengue (December 2025), severe fever with thrombocytopenia syndrome (October 2025) and rabies (July and September 2025). The Department of Disease Control’s July 2026 figures for Streptococcus suis, leptospirosis and melioidosis, given above, are the most recent Thai warnings that touch on food and water.