12 teams are directly qualified for the preliminary round (TH: Champions League title holders).

[1] The draw for the group stage was held on 29 August 2017 in Budapest.

The group winners, runners-ups, third and fourth placed teams advance to the Final 8.

The matchdays are 25 October, 8 and 29 November, 9 and 20 December 2017, 13 and 24 January, 7 and 28 February, 14 and 31 March, 18 and 28 April, 9 May 2018.

[3] (Pro Recco) Josip Vrlić (Barceloneta) Maro Joković (Jug)