I know that the requirement is for 800,000 baht in a bank account for 3 months to qualify for a retirement visa, but is it ok to have a foreign currency account in a Thai bank, which when converted comes to an amount greater than 800,000 baht?

It has been accepted in the past but would be best to check with office you plan to use.

Thanks for the information Lopburi3, but has anyone actually tried this at the immigration office?

I would not have said it had been accepted in the past if people have not reported that it had. We are talking only about accounts in Thai located banks, which I believe is what you are talking about from your post. But I would not rely on what has worked as being a sure thing. If you want more specific information you will have to provide the office location and keep in mind that one officer may say one thing and another something a bit different even in the same office.

I know that the requirement is for 800,000 baht in a bank account for 3 months to qualify for a retirement visa, but is it ok to have a foreign currency account in a Thai bank, which when converted comes to an amount greater than 800,000 baht?

IMHO the Immigration Dept require a letter from a Thai bank confirming B800,000 in an account in your name.

I know that the requirement is for 800,000 baht in a bank account for 3 months to qualify for a retirement visa, but is it ok to have a foreign currency account in a Thai bank, which when converted comes to an amount greater than 800,000 baht?

IMHO the Immigration Dept require a letter from a Thai bank confirming B800,000 in an account in your name.

They also want to see your bank book that will say what currency the acc.is

In all probability this will be acceptable, but we all know there will always be the office that will not accept it.

Ask them and find out.