Israeli and Thai officials have said the plot was aimed at Israeli diplomats in Bangkok, the capital, though Iran denied the allegations and neither defendant was charged with terrorism or attempting to kill Israelis.
A Thai court sentenced Saeid Moradi, 29, to life in prison for attempting to murder a police officer and possessing explosives that damaged property and injured several civilians. It sentenced Mohammad Kharzei, 43, to 15 years in jail for possessing explosives.
The pair was detained in February 2012, shortly after a cache of homemade explosives accidentally blew apart their villa. Both claimed innocence, saying they had been unaware of the explosives in their home.
Defence lawyer Kittipong Kiattanapoom said he would consult with both men and their families to find out if they want to appeal.
Moradi, a factory technician from Tehran and a former soldier, had faced a death sentence.
He lost his legs as he tried to flee the villa on a crowded Bangkok street. He was carrying explosives from the house and dropped them in the street as police chased him.
Moradi had said he was carrying the explosives out of the house in an attempt to dispose of them. He also said he was not aware that the explosives were similar to "sticky" bombs used against Israeli diplomats in foiled attacks a day before the Bangkok incident in India and Georgia.
Kharzei has testified that he was not a terrorist and had nothing to do with the explosions. He says he had not known Moradi until they met at an airport in Tehran before boarding their flight to Thailand.
Another suspect, Iranian Masoud Sedaghatzadeh, 31, was detained in Malaysia, where he has appealed an extradition order. He met Moradi and Kharzei in the Thai city of Pattaya, and fled to Malaysia the day after the explosion.
Israel believes the botched plot was part of a covert war against Israeli interests abroad that has intensified in recent years because of Iran's alleged quest to develop nuclear weapons.