A Thai female friend, legally married to an American Citizen, already has a US Tourist Visa (with a 10 year validity, unused so far).

If she travels to the US on that Visa is it possible to convert to - or apply for a new - Immigrant Visa, while in the US, on the basis of being married to a US Citizen or does she have to leave on the Tourist Visa and apply for an Immigrant Visa when back in Thailand?

Patrick

In short, yes, it can be done. The process is called Adjustment Of Status. Do a Google for it, lots of hits.

It can be problematic, tho. If U.S. Immigration determines that this was the intent of the particular "tourist" visit to the U.S., they may well deny the request and determine that the tourist visa was obtained with fraudulent intent. Not good!

The great www site, www.visajourney.com, has some discussions on this issue, here's just one:

http://www.visajourney.com/forums/topic/515007-adjustment-of-status-after-entering-the-us-on-a-b2-visa/

Best way to immigrate to the U.S. is via an Immigrant Visa, which sad to say, can be time consuming.

Mac