I believe it will be on your immigration record forever, however you are eligible to apply for a waiver. (I believe if "not less than 15 years since the acts were committed" The trouble is, depending on what you did, they may consider it an "aggravated felony" and render you inadmissible. The passage of time is on your side. But there are alot of factors you have to consider, as well as what your intentions are.. visitors visa, student visa etc... Good luck
P.S. Google "aggravated felony" and look up the Homeland security immigration site for more info
