Former Enron executives Ken Lay and Jeffrey Skilling will enter court today on fraudcharges.
The case comes to trial more than four years after what was once the seventh-largest US company collapsed into bankruptcy and is expected to last four months.
Mr Lay (63), who led the company for 15 years before handing over the chief executive position to Mr Skilling, faces seven charges, including conspiracy and fraud.
Those charges are linked mostly to the few months he returned to serve as chief executive after Mr Skilling resigned and before Enron's bankruptcy filing. Mr Skilling (52) faces 31 charges including conspiracy, fraud and insider trading.
Unlike Mr Lay, who is expected to say he knew nothing of any illicit activities at the company, Mr Skilling has indicated he will argue the company did nothing illegal, and that it collapsed due to a run on its bank accounts by nervous creditors.
Enron was praised as an energy market innovator before it imploded in 2001 when its illicit use of off-balance-sheet partnerships to hide billions of dollars in debt and pump up earnings was unveiled.
The energy trader's demise left thousands jobless and wiped out billions of dollars in workers' retirement accounts - a factor that defence lawyers complained has created a tainted jury pool made up mostly of people who are already biased against the two men.