A Harvard Business School graduate and former consultant, Skilling, 52, is accused of lying to investors and employees about Enron's financial health while being aware of the corporation's dubious accounting practices and weak business ventures.
At one time the seventh largest corporation in the United States, Enron declared bankruptcy in December 2001, forcing 4,000 people out of their jobs and costing investors millions of dollars.
"His testimony may be his only opportunity to save himself, but at the same time, he runs the risk of sealing his fate and almost guaranteeing his conviction if jurors find his testimony incredible," said Robert Mintz, a former federal prosecutor, reported the Associated Press.
Skilling told reporters Thursday that he is "innocent of all charges that have been put forward."
"I have nothing to hide," he said, echoing a statement from his appearance in front of a U.S. Senate subcommittee in February 2002.
Skilling is not expected to be questioned by prosecutors until mid-week, perhaps later.
Legal experts say the Skilling defense team is trying to focus blame for Enron's allegedly illegal transactions onto former Chief Financial Officer Andrew Fastow, who, according the AP, admitted to stealing from Enron through fraudulent partnerships and struck a plea deal to cooperate with prosecutors in exchange for a 10-year prison sentence.
Fastow also has said he "engaged in secret deals with Skilling to move poor performing assets to Fastow's [off shore] partnerships to 'juice' Enron's earnings," reported CNN.
Nonetheless, the defense is trying to paint Skilling as a strategic thinker who took the advice of outside lawyers and accountants.
Last week, Jim Derrick, Enron's former general counsel, said Skilling and Kenneth Lay -- Skilling's former boss who is set to testify later -- sought expert legal advice when former Enron Vice President Sherron Watkins expressed concern about improper accounting procedures in a now infamous memo.
Skilling and Lay turned to the law firm Vinson and Elkins, which said no immediate action was necessary, reported the Chicago Tribune.
The defendants face potentially 20 to 30 years in jail if convicted, according to CNN.