"I think it's important to put it into perspective - I tried it," Chafee, 46, told WJAR-TV in an interview. "It's not something I'm proud of."
Chafee, the mayor of Warwick, said he decided to speak publicly about his cocaine use following "dogged" questioning about whether Republican presidential candidate George W. Bush used drugs.
An interviewer posed the question to Chafee during the Friday taping of a news show.
"I had three choices: Lie, which was not an option, or evade it and receive the consequences of that, or be honest. And I chose to be honest," Chafee told the Associated Press after the broadcast.
Chafee said he tried cocaine while a student at Brown University. He graduated in 1975.
Chafee is the sole Republican running for the Senate seat. The race has also attracted Rep. Robert Weygand, D-R.I., former Democratic Lt. Gov. Richard Licht, and former state Attorney General Arlene Violet, who may run as an independent.
The Providence Journal reported Monday that Weygand admitted to experimenting with marijuana - but not heroin or cocaine - while at the University of Rhode Island. Licht and Violet both said they had never used illegal drugs.
Chafee acknowledged that his admission could hurt his candidacy if voters hold him to the wholesome image of his father, John Chafee, a former Boy Scout and World War II hero.
"It's not something positive for my record," he said.
Said Violet: "I think his personal involvement with cocaine is going to be between him and the voters."
The elder Chafee announced earlier this year that he would not seek a fifth term as senator in 2000. Chafee, 76, was secretary of the Navy and a three-term Rhode Island governor before he became a senator.
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