The Thai greeting referred to as the wai (Thai: ไหว้) Or in Lao as "Kub" consists of a slight bow, with the palms pressed together in a prayer-like fashion.

It is also common as a way to thank someone or apologise.

Origin

The wai originated from an ancient greeting that was done to show neither individual had any weapons. There exist multiple versions of the greeting based on social class, gender, and age.

One speculation is that it comes from the Buddhist Religion. After certain prayers, one must clasp their hands together and bring it down towards the ground three times.

The higher the hands are held in relation to the face, the more respect/reverence the the giver of the wai is showing.

Extracted from Wikipedia: The Wai

first time in thailand i was running about giving the wai to everyone big mistake

I never wai as i am not Thai or Buddhist.

When i see a farang do it, it looks kinda weird to me.

It is not wrong for a falang to wai, however it is wrong to Wai to people younger than yourself, and as I am one of the older buggers on this site I very rarely wai

I invariably cringe when I see farangs giving a wai as it is patently obvious that the vast majority have not got a clue how to do it correctly. As for giving a wai to service staff ...................

Farangs are not expected to wai but should always acknowledge a wai. A simple nod of the head, which I do, is sufficient.

Alan

While I agree that it looks strange for a falang to wai at Thai, it is considered a show of respect to wai someone of superior position to you. Therefore, it is good to wai a doctor, should you go to the hospital, or wai someone who holds a high government position (particularly if you are visiting their office). I haven't yet been in such a situation, but will later this week, and hope I remember to wai.

There's nothing wrong with a farrang Wai-ing as long as he does it correctly and at the right level, its a sign of respect especially if your meeting the future in-laws,
Its pathetic when you see one farrang Wai-ing another....

No one expects it, so I never do it. Seems to be quie impotant to Thais, and think their class system is quite complex and far too subtle for us farangs to get involved with. Its our money they seem to respect most
.

Marky

I just got back from Thailand I was there for 6 wks.Three wks in Pattaya and three in my wife's village.It was 18 months since I've been back and the fourth trip here.I was really was surpised and so was my wife how in Patttaya the people hardly every wai anymore.It's starting to remind me of LasVegas,where you get treated like a number and they figure there never going to see you again.Now back in the village eveyone one wai's and greets you with much kindness.There is a study how resort areas really hurt the people in those commutinties.They no longer can afford to live there or own homes,rising crime rates and murder goes up also.I belive this we be the new Pattaya with in a few yrs.That's a shame.

The etiquette concerning wai's is so difficult to understand that i don't think anyone other than a Thai could understand it. For that reason i have give up on doing it now as i reckon the Thais just cringe when they see farangs do it.

I haven't seen a slowdown in wai's around Thailand.

Anyway, people please don't wai little kids. It makes you look like a clown.

As I planing my first trip to Thailand and by reading your comments here I came to conclusion that not to make yourself clown in front of others it is better just to use "thank you" or "hello" when appropriate. And use "wai" only when you are communicating with: doctors, police, government or older people.

please correct me if my understanding is wrong.
thanks