You won’t have a hard time finding Thai food in Vientiane. In whole Laos, you have it the easiest here. You just have to walk the streets and it is almost guaranteed that you’ll see a few Thai dishes. On the street, however, much has a more Laotian taste. This is partly due to the spices used by the locals. So, it’s hard to say if it really is Thai or more Laotian food. The same applies to the larger markets. Here you have but self-explanatory more choices.
If the Laotian taste doesn’t appeal to you, you can also find authentic Thai food. For that you just have to visit a Thai restaurant. A potential option would be the Bangkok Noi. The restaurant has an impeccable reputation. For many it is one of the best Thai restaurants in Vientiane. The selection is good, the quality of the food is good and everything is relatively cheap. Although a bit more expensive than most other Thai food. But you definitely don’t have to pay much. Well, still the Bangkok Noi is definitely not the only good Thai restaurant in Vientiane. There are definitely others.