On February 2, 2004, scientists working at the Joint Institute for Nuclear Research in Dubna, Russia, along with scientists from the U.S. Department of Energy's Lawrence Livermore National Laboratory, announced the creation of ununtrium. In experiments performed between July 14, 2003 and August 10, 2003, atoms of americium-243 were bombarded with ions of calcium-48 using a device called a cyclotron. This produced one atom of ununpentium-287 and three atoms of ununpentium-288. All four atoms of ununpentium quickly decayed into ununtrium through alpha decay.

Ununtrium's most stable isotope, ununtrium-284, has a half-life of about 0.48 seconds. It decays into roentgenium-280 through alpha decay.

Since only a few atoms of ununtrium have ever been produced, it currently has no uses outside of basic scientific research.