[5][6] The top six placed teams from the top-tier level Greek Basket League's 2018–19 season, gained an automatic bye to the 2019–20 Greek Cup quarterfinals.

While the eight lower-placed teams from the 2018–19 Greek Basket League season; along with all of the teams from the 2nd-tier level Greek A2 Basket League's 2018–19 season, and the 3rd-tier level Greek B Basket League's 2018–19 season, played in preliminary rounds, competing for the other two quarterfinals places.

Note: Ippokratis Kos decided to forfeit their game against Farsalon.

Referees: Schinas, Anastopoulos, Karakatsounis AEK (Papatheodorou): Ray 16, Zisis 11, Mačiulis 9, Giannopoulos 6, Slaughter 5, Janković 4, Toliopoulos 3, Chalmers 3, Chrysikopoulos 2, Grant 2, Rogkavopoulos, Mavroeidis.

Promitheas Patras (Giatras): Kaselakis 15, Mavrokefalidis 11, Hall 9, Babb 8, Lypovyy 7, Mantzaris 3, Agravanis 2, Fieler 2, Katsivelis, Jones, Bell, Mantzoukas.