The following 44 teams from the 10 CONMEBOL associations qualified for the tournament, entering the first stage:[3] A further 10 teams eliminated from the 2018 Copa Libertadores were transferred to the Copa Sudamericana, entering the second stage.

[14] The draw for the first stage was held on 20 December 2017, 20:00 PYST (UTC−3), at the CONMEBOL Convention Centre in Luque, Paraguay.

[18] The draw for the second stage was held on 4 June 2018, 20:00 PYT (UTC−4), at the CONMEBOL Convention Centre in Luque, Paraguay.

If still tied, extra time would not be played, and the penalty shoot-out would be used to determine the winner (Regulations Article 27).

If still tied, extra time would not be played, and the penalty shoot-out would be used to determine the winner (Regulations Article 27).