After months of negotiations among Tunisia's political parties, the assembly approved October 26 for the legislative election and November 23 for the first round of the presidential poll.
Some 125 deputies voted in favour of the timetable, which also envisages a presidential run-off before the end of 2014, while 15 voted against and 17 abstained.
"It's a historic step. We are pleased that the electoral calendar has been fixed, because it gives hope for the future of Tunisia," MP Mahmoud Baroudi said.
Since the revolution that toppled longtime autocrat Zine El Abidine Ben Ali in January 2011, Tunisians have awaited the formation of permanent state institutions.
Ahead of the debate on the election law, assembly speaker Mustapha Ben Jaafar stressed "the crucial importance ... Of this last stage in the constituent process."
The political parties only agreed on the order of the elections earlier this month, with the parliamentary poll taking place before the presidential vote.
Kamel Toujani, a member of the ISIE, said the adoption of the electoral law was a relief.
"The situation is clearer. Now we must continue our work. The biggest challenge is the registration of voters," he said.
Around 7.5 million Tunisians are eligible to vote, but only 4.1 million registered in 2011, for the first poll after the uprising that toppled Ben Ali and sparked similar revolts across the region.
