Can you drink tap water?
No — and this is the single most important thing to know about water in Bangkok. The Metropolitan Waterworks Authority treats water to drinkable standards at the plant, but Bangkok buildings range from new to 60 years old, and older pipes leach contaminants. Even Thais who have lived here their whole lives drink bottled or filtered water exclusively. Tourists who drink from the tap usually end up with a stomach upset within days.
Hotels supply 1-2 free bottles per day. Once those run out, every 7-Eleven, Family Mart, and supermarket sells water everywhere you go — there is no situation in Bangkok where clean water is more than 200 meters away.
Bottled water prices
At 7-Eleven a 600ml bottle is 7-10 baht and a 1.5L bottle is 13-15 baht. Brands like Singha, Crystal, and Nestle Pure Life are all reliable. At supermarkets 6-liter jugs cost 35-50 baht — worth it if you are staying somewhere with a kitchen. Restaurants charge 20-40 baht for a small bottle, which is fine.
Avoid buying water at the airport or major tourist sites where prices triple. A 7-Eleven is usually within 5 minutes walk of any neighborhood.
Is the ice safe?
Yes, in 99% of cases. Bangkok ice is mostly factory-made from purified water, and any restaurant, cafe, or hotel uses it. The visual giveaway is the shape: cylindrical ice cubes with a hole through the middle (or perfect rectangles) come from a factory. Avoid only crushed or chipped ice from a remote roadside cart in a non-tourist area, which occasionally comes from frozen tap water.
Iced coffee, fruit shakes from market stalls, and bar cocktails all use factory ice. Drink them without worry.
Brushing teeth and showering
Brushing teeth with tap water is fine for adults. The water hits your mouth for under a minute, and you spit most of it out. Travelers with very sensitive stomachs or parents traveling with toddlers sometimes use bottled water as extra insurance, but it is not necessary for most people.
Showering, washing your face, and washing dishes with tap water are all completely safe. Just keep your mouth closed in the shower out of habit. Contact lens wearers should use saline or bottled water for rinsing lenses, never tap.
Restaurants and street food
Restaurant water is safe to drink — it comes from large filtered jugs or bottles. If a restaurant pours from a clear pitcher onto your table, it is filtered. Soup, coffee, and tea are all boiled and pose zero risk. Fresh fruit shakes use factory ice and bottled water. The one thing to ask about is sliced fruit that has been sitting on display in heat, which is more about temperature than water.
Refill stations and sustainability
Bangkok has a growing refill network — many cafes, hostels, and gyms now offer free filtered water if you bring a bottle. Apps like RefillMyBottle map them. A reusable bottle saves 100+ plastic bottles on a two-week trip. Most BTS stations also have water vending machines that dispense filtered water for 1 baht per liter into your own bottle.