You can have dual citizenship in the U.S.. It did used to be the case in the US that you couldn't hold dual citizenship (except in certain cases if you had dual citizenship from birth or childhood, in which case some Supreme Court rulings -- Perkins v. Elg (1939), Mandoli v. Acheson (1952), and Kawakita v. U.S. (1952) -- permitted you to keep both). . Most of the laws forbidding dual citizenship were struck down in 1967 by the US Supreme Court. The court's decision in this case, Afroyim v. Rusk, as well as a second case in 1980, Vance v. Terrazas, eventually made its way explicitly into the statute books in 1986; up till that time, the old laws were still on the books, but the State Department was effectively under court order to ignore them. . The official US State Department policy on dual citizenship today is that the United States does not favor it as a matter of policy because of various problems they feel it may cause, but the existence of dual citizenship is recognized in individual cases. In other words, ask them if you ought to become a dual citizen, they will recommend against doing it; but if you *tell* them you are a dual citizen (but of course, you have to o.k it with the other country), they'll usually say it's OK. . A lot of the times it depends on the individual countries. Most countries do not recognize dual citizenship or some countries your parents have to have been born there or for example Ireland, you have to have at least 1 grandparent that was born there to have citizenship by decent, for Sri Lanka, it can go back to Great grandfather.. CHECK OUT THIS SITE BELOW- it has listings of all countries and their laws and regulations on citizenship. . It helped me =)