The BBC reports that Malam Bacai Sanha, and former military ruler Joao Bernardo Vieira are both vying for the job and say they can bring calm to politics in the West African state.
Sanha was the top vote-getter in the first round of elections in June.
Former President Kumba Yala failed to get enough votes to qualify for the run-off.
1.5 million people live in the former Portuguese colony.
Susan Sarandon: I was stoned at almost every awards show
Penelope Cruz named 2013's 'Best Body' by Fitness magazine