The "bribes-for-contracts" scheme netted the Los Angeles couple about $13.5 million, Lopez said.
"This case is about greed, it's about corruption and it's about deceit," Lopez told the seven man-five woman jury. The Greens "turned TAT into their own personal piggy bank," he said.
The couple have pleaded not guilty to charges including conspiracy and money laundering. If convicted, they each could receive up to life in prison. Both are free on bond.
Juthamas has denied any wrongdoing and has not been charged in Thailand.
The Greens are the first entertainment industry figures who have been charged under the Foreign Corrupt Practices Act, a federal statute prohibiting corrupt payments to foreign officials for business purposes.
Prosecutors contend the Greens paid Juthamas about $1.8 million to help secure the Bangkok film festival and tourism-related deals between 2002 and 2007. The payments, some of which were paid in cash to Juthamas directly, were often disguised as sales commissions, ranging between 10 percent and 20 percent, Lopez said.
The Greens inflated their budgets so Juthamas could be paid off, prosecutors said.
"The simple question for you as jurors is whether all these payments to overseas accounts were bribes so they (Greens) can get the inside track for those contracts," Lopez said.
Attorney Jerome Mooney, who represents Gerald Green, said the payments made to Juthamas' daughter were legitimate because his 77-year-old client had entered into a consulting agreement with her.
Marilyn Bednarski, Patricia Green's lawyer, shot down Lopez's contention that the couple profited heavily from the contracts. She showed jurors tax returns from 2000 - before the couple ran the film festival - and from 2006, the festival's most successful year. The difference was only about $100,000, she said.
"In this case , you will be able to follow every penny that went into the Greens' account," Bednarski told jurors. "There is no sleight of hand here."
The Southern California couple helped transform the festival into a rising star on the international circuit for screening new films, attracting the likes of Michael Douglas, Jeremy Irons and director Oliver Stone to Thailand.
Juthamas, who is no longer Thailand's tourism governor, ran for a parliamentary seat in 2007 but pulled out of the race after the allegations surfaced. Though she faces no charges, Maj. Gen. Piyawat Kingket, chief of the Department of Special Investigation's Special Unit, said the police have found evidence against her.
Gerald Green's career in Hollywood spans more than 30 years, pairing up with Stone on "Salvador," which was nominated for two Academy Awards, and serving as executive producer on the Christian Bale-led "Rescue Dawn" in 2006.
Patricia Green, 54, produced "Diamonds," a comedy starring Kirk Douglas and Lauren Bacall, with her husband.