The six-count indictment alleges that one of the most dominant pitchers of his era obstructed a congressional inquiry with 15 different statements made under oath, including denials that he had ever used steroids or human growth hormone. As he did when he testified to a House committee in 2008, the seven-time Cy Young winner denied using the substances again Thursday and said he will fight to clear his name.
"I never took HGH or Steroids. And I did not lie to Congress," Clemens said on Twitter. "I look forward to challenging the Governments accusations, and hope people will keep an open mind until trial. I appreciate all the support I have been getting. I am happy to finally have my day in court."
Clemens is just the latest superstar to be ensnared in baseball's steroid scandal. All-time home run king Barry Bonds is scheduled to go on trial in March on charges of lying to a federal grand jury when he said he never knowingly used performance-enhancing drugs. Slugger Mark McGwire admitted earlier this year to using steroids.
Clemens, who turned 48 this month, ranks ninth on the career list with 354 victories and was an 11-time All-Star. During a 23-year career that ended in 2007, he played for the Boston Red Sox, the Toronto Blue Jays, the Yankees and the Houston Astros and struck out 4,672 with a lifetime 3.12 ERA.
The rampant use of performance-enhancing drugs in the 1990s and early 2000s has been one of baseball's worst scandals. The indictments against Clemens raise new questions about whether the superstar will ever be enshrined in the sport's Hall of Fame - and might instead spend time in prison.
Clemens also used his lawyer Thursday to insist that he was telling the truth.
"Roger is looking forward to his day in court," the athlete's lawyer, Rusty Hardin, told a news conference. "He is happy this has finally happened. We have known for some time this was going to happen. We'll let everything get taken care of in court."
Hardin said federal prosecutors made Clemens a plea offer but he rejected it. Hardin declined to comment on details of the proposed plea deal - which ordinarily involves admitting to a crime while avoiding the scenario of a multiple-count indictment as happened in the Clemens case.
Clemens' case was assigned to U.S. District Judge Reggie Walton, who presided over the perjury and obstruction trial of Vice President Dick Cheney's former chief of staff, I. Lewis "Scooter" Libby. No date was set for Clemens' initial court appearance.
The former pitcher faces a combined maximum sentence of 30 years in prison and a $1.5 million fine if convicted on all charges.
However, under U.S. sentencing guidelines, he would probably face no more than 15 to 21 months in prison.
Hardin said that although many have argued that Clemens should simply admit he took steroids, "the problem is nobody ever talks about what he should have done if he didn't do it."
"And he didn't do it and he's adamant about that and always has been. Today is just another continuing part of that saga," Hardin said.
Clemens had been prominently mentioned in the Mitchell Report, Major League Baseball's own accounting of its steroid problem, and he went to Capitol Hill on his own to clear his name in 2008.
"Let me be clear," he told lawmakers. "I have never taken steroids or HGH."
What once seemed to be a he-said vs. he-said dispute between Clemens and his former trainer, Brian McNamee, once the New York Yankees' strength and conditioning coach, escalated into a federal case.
Clemens and McNamee testified under oath at the 2008 hearing before a House committee and contradicted each other about whether the pitcher had used PEDs. The grand jury heard testimony from McNamee, who gave federal authorities syringes he said were used to inject Clemens with drugs.
McNamee has said he injected Clemens more than a dozen times with steroids and HGH from 1998 to 2001. Clemens says McNamee was lying.
"As far as we're concerned, it's vindication," Earl Ward, one of McNamee's attorneys, said of the indictment.
Clemens was singled out by name 82 times in the 409-page report, compiled by former Senate Majority Leader George Mitchell and released in December 2007. Much of the information on Clemens came from McNamee.
Former MVP Jose Canseco, who has admitted his own steroid use and accused others, was the most-mentioned player in the Mitchell Report with 105 references.
"I am saddened to hear of the indictment of my friend and former teammate, Roger Clemens," Canseco said in a statement through his attorney. "I am not aware of any use of steroids by Roger."
Major League Baseball did not comment on the indictment. But at least two former teammates expressed support for Clemens.
"In my opinion, he's a Hall of Famer. Period," said New York Yankees slugger Lance Berkman, who played with Clemens in Houston.
"Whatever you want to say about the guy, he belongs in the Hall of Fame. In my opinion, legacy-wise, I guess that's up to - I mean, 200 years from now, who cares?
"But in the short term, I guess, he may have some things to address," Berkman said. "He's a big boy. He'll face up to whatever it is. But it doesn't change my opinion of him at all."
Yankees catcher Jorge Posada, who played with Clemens on two World Series championship teams, said he would back his former teammate.
"I'm going to support him and I'm going to be behind him and that's all I can say," Posada said.
Longtime Clemens friend and teammate Andy Pettitte told congressional investigators that Clemens confided to him that he had used HGH.
"I believe Andy has misheard" the conversation, Clemens responded. He said he had simply mentioned to Pettitte a TV show about three older men who used HGH to get back their quality of life.
Pettitte was taking part in a charity event after New York's 11-5 win over Detroit at Yankee Stadium on Thursday and wasn't immediately commenting, the team said.