Last updated: October 2026
Quick answer
No, don’t drink tap water straight from the tap in Thailand. Bangkok’s water is treated, but it can pick up contamination from old pipes and building tanks before it reaches your tap. Drink sealed bottled water or filtered water instead. Brushing your teeth with tap water is fine for most healthy adults, boiled water is safe to drink, and ice from established restaurants and hotels is generally safe.
Key Takeaways on Thailand Tap Water
- Don’t drink tap water in Thailand, including in Bangkok hotels, unless it has been filtered or boiled.
- Sealed bottled water is cheap and sold everywhere; check the seal is intact.
- Boiling tap water kills germs, so boiled water, tea and coffee are safe to drink.
- Brushing your teeth with tap water is fine for most healthy adults; just don’t swallow it.
- Ice in restaurants, cafés and hotels is usually factory-made from purified water.
Can You Drink Tap Water in Thailand?
It’s best not to. The Metropolitan Waterworks Authority (MWA), which supplies Bangkok, treats its water and says it meets World Health Organization drinking-water guidelines when it leaves the treatment plant. The problem is the journey to your tap: older pipes and the water tanks on many buildings can let bacteria and other contaminants back in. Outside Bangkok, water quality varies even more.
That’s why most Thai residents don’t drink water straight from the tap either. They buy bottled water, use filters at home or fill up at refill machines.
What Is Safe, and What Isn’t?
| Water | Safe? | Notes |
|---|---|---|
| Tap water, straight from the tap | No | Can be contaminated by old pipes and building tanks. |
| Sealed bottled water | Yes | Cheap and sold at every 7-Eleven and street stall. Check the seal. |
| Boiled tap water | Yes | Boiling kills bacteria, viruses and parasites. Tea and coffee made with boiling water are fine. |
| Hotel and restaurant water dispensers | Usually | Most use filtered water. Ask if unsure. |
| Street refill machines | Usually | Filtered water, often just a baht or two per litre. Choose clean, well-kept machines. |
| Ice in restaurants, cafés and hotels | Usually | Factory ice (cubes or cylinders with a hole in the middle) is made from purified water. |
| Brushing your teeth with tap water | Yes, for most people | Don’t swallow it. Use bottled water if you have a weak immune system. |
Is Boiled Tap Water Safe to Drink in Thailand?
Yes. Bringing water to a full, rolling boil kills the bacteria, viruses and parasites that cause stomach upsets, which is why hot drinks and soups are safe. Boiling doesn’t remove chemicals, so if you’re staying long-term, a good home filter or bottled water is the more practical choice for everyday drinking.
Is the Ice Safe in Thailand?
Generally, yes, in restaurants, cafés, bars and hotels. Most ice in Thailand is made in factories from purified water and delivered in sealed bags; it’s often shaped as cylinders with a hole in the middle. Be more careful with crushed ice from a large block at small street stalls, where the ice may have been handled or stored less hygienically.
Can You Brush Your Teeth With Tap Water?
For most healthy adults, yes. You only take in a tiny amount, and you spit it out. If you have a weakened immune system, are travelling with young children, or simply want to be extra careful, use bottled water instead.
What If I Accidentally Drank Tap Water?
Don’t panic. A mouthful or a glass of tap water usually causes no problems at all. If you do get an upset stomach, it typically starts within a few hours to a couple of days and settles within 1–3 days.
- Stay hydrated with bottled water and oral rehydration salts, available at any Thai pharmacy.
- Eat lightly: plain rice, toast, bananas or rice porridge (jok).
- Check with a doctor or pharmacist before taking anti-diarrhea tablets, especially if you have a fever.
Read more: how to avoid food poisoning in Thailand and the best over-the-counter medicines for diarrhea in Thailand.
Upset stomach in Bangkok?
See an English-speaking doctor today. Walk in or book a same-day appointment at our clinics in Asok, Sathorn or Phrom Phong, open daily 08:00–18:30. Consultations from ฿700. Too unwell to travel? Our medical team can visit your hotel or home anywhere in Bangkok.
When to See a Doctor
- Diarrhea lasting more than 2–3 days, or getting worse
- A high fever
- Blood or mucus in your stool
- Severe stomach pain
- Vomiting so much you can’t keep fluids down
- Signs of dehydration: very little or dark urine, dizziness, a dry mouth or extreme tiredness
Young children, older adults, pregnant women and people with long-term conditions should see a doctor sooner.
Tips for Staying Hydrated in Thailand
- Carry a refillable bottle and top it up at hotel dispensers or refill machines.
- Drink regularly through the day; the heat and humidity make you sweat more than you notice.
- Coconut water and electrolyte drinks help on very hot days or after exercise.
- Go easy on alcohol in the heat, as it adds to dehydration.
About HealthDeliver Clinic Bangkok
HealthDeliver Clinic, with locations in Asok, Sathorn and Phrom Phong, is a family-friendly medical centre providing care for people of all ages, from infants to the elderly. For tourists in Bangkok, we offer quick access to English-speaking doctors, whether you walk into one of our clinics or need a hotel visit because you’re too unwell to travel. See doctor consultation options and prices.
Frequently Asked Questions About Tap Water in Thailand
Can you drink tap water in Thailand?
It’s best not to. Tap water is treated, but it can be contaminated by old pipes and building water tanks before it reaches the tap. Drink sealed bottled water, filtered water or boiled water instead.
Is Bangkok tap water safe to drink?
Bangkok’s water supplier, the Metropolitan Waterworks Authority, says its water meets WHO guidelines when it leaves the treatment plant. Pipes and building tanks can contaminate it afterwards, so it’s safer not to drink it straight from the tap.
Is boiled tap water safe to drink in Thailand?
Yes. A full, rolling boil kills the bacteria, viruses and parasites that cause stomach upsets. Boiling doesn’t remove chemicals, so for everyday drinking, bottled or filtered water is more practical.
Is the ice safe in Thailand?
Generally, yes, in restaurants, cafés, bars and hotels. Most ice is factory-made from purified water, often shaped as cylinders with a hole in the middle. Take more care with crushed block ice at small street stalls.
Can I brush my teeth with tap water in Thailand?
For most healthy adults, yes, as long as you spit it out. Use bottled water if you have a weakened immune system or for young children.
What should I do if I accidentally drank tap water in Thailand?
Usually nothing. A small amount rarely causes problems. If you get an upset stomach, drink bottled water with oral rehydration salts, eat lightly and see a doctor if it lasts more than 2–3 days or you have a high fever or blood in your stool.
Are water refill machines safe in Thailand?
Usually. Street refill machines provide filtered water for a baht or two per litre. Choose machines that look clean and well maintained.
When should I see a doctor for diarrhea in Bangkok?
See a doctor if diarrhea lasts more than 2–3 days or you have a high fever, blood or mucus in your stool, severe stomach pain, can’t keep fluids down or show signs of dehydration. HealthDeliver’s English-speaking doctors see walk-in and same-day patients in Asok, Sathorn and Phrom Phong, and can visit your hotel.