Aucas and Mushuc Runa were relegated from the Serie A after accumulating the fewest points during the 2016 season.
They were replaced by Macará and Clan Juvenil, the 2016 Serie B winner and runner-up, respectively.
The first stage began on January 29 and ended on July 9.
The winners were the Serie A champions and earned the Ecuador 1 berth in the 2018 Copa Libertadores, and the losers were the Serie A runners-up and earned the Ecuador 2 berth in the 2018 Copa Libertadores.
By having the greater number of points in the aggregate table, Delfín played the second leg at home.