See main article: 2017–18 EHF Champions League. This article describes the knockout stage of the 2017–18 EHF Champions League.[1]
The top six placed teams from each of the two groups advanced to the knockout stage.
| Group | width=200 | Qualified for quarterfinals | width=200 colspan=5 | Qualified for Round of 16 | ||
|---|---|---|---|---|---|---|
| First place | Second place | Third place | Fourth place | Fifth place | Sixth place | |
| A |  Vardar |  Barcelona Lassa |  HBC Nantes | Rhein-Neckar Löwen |  MOL-Pick Szeged |  IFK Kristianstad |
| B | Paris Saint-Germain | Telekom Veszprém | Flensburg-Handewitt | THW Kiel |  PGE Vive Kielce |  Meshkov Brest |
| Playoff winners | Skjern Håndbold Montpellier |
12 teams played home and away in the first knock-out phase, with the 10 teams qualified from groups A and B and the two teams qualified from groups C and D. After that, the six winners of these matches in the first knock-out phase joined the winners of groups A and B to play home and away for the right to play in the final four.
|}
Montpellier won 56–55 on aggregate.----Skjern Håndbold won 61–59 on aggregate.----HBC Nantes won 60–52 on aggregate.----Flensburg-Handewitt won 53–46 on aggregate.----PGE Vive Kielce won 77–47 on aggregate.----THW Kiel won 56–50 on aggregate.
|}
Vardar won 56–56 on aggregate on away goals.----Paris Saint-Germain won 69–60 on aggregate.----Montpellier won 57–45 on aggregate.----HBC Nantes won 60–54 on aggregate.
The final four was held at the Lanxess Arena in Cologne, Germany on 26 and 27 May 2018.[2] The draw was held on 2 May 2018.[3] [4] [5] [6]
----