The qualification structure was the same as for the previous five tournaments. The ten teams played in a league of home-and-away round-robin matches. The top four teams qualified for the 2018 FIFA World Cup, and the fifth-placed team advanced to the inter-confederation play-offs. Unlike previous qualifying tournaments where the fixtures were pre-determined, the fixtures were determined by draw, which was held as part of the 2018 FIFA World Cup Preliminary Draw on 25 July 2015, starting 18:00 MSK, at the Konstantinovsky Palace in Strelna, Saint Petersburg, Russia. For scheduling reasons, Argentina and Brazil were automatically positioned as Teams 4 and 5 respectively to ensure that no team has to play both of them on any double matchday. The remaining eight teams were drawn into one of the remaining eight positions from Teams [|1] to 10.
Entrants
All 10 national teams from CONMEBOL entered qualification. Note: Bolded teams qualified for the World Cup. Peru advanced to the inter-confederation play-offs and won.
Draw position
Team
FIFA ranking at start of event
1
'
5
2
9
3
61
4
'
1
5
'
7
6
31
7
69
8
67
9
'
50
10
20
Schedule
There were a total of 18 matchdays: four in 2015, eight in 2016, and six in 2017.
The inter-confederation play-offs were scheduled to be played between 6–14 November 2017. The fixtures for CONMEBOL qualification were decided based on the [|draw positions], as follows:
Standings
Matches
Matchday 1
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Matchday 2
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Matchday 3
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Matchday 4
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Matchday 5
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Matchday 6
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Matchday 7
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Matchday 8
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Matchday 9
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Matchday 10
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Matchday 11
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Matchday 12
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Matchday 13
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Matchday 14
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Matchday 15
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Matchday 16
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Matchday 17
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Matchday 18
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Inter-confederation play-offs
The draw for the inter-confederation play-offs was held as part of the 2018 FIFA World Cup Preliminary Draw on 25 July 2015, starting 18:00 MSK, at the Konstantinovsky Palace in Strelna, Saint Petersburg. The fifth-placed team from CONMEBOL was drawn against the first-placed team from OFC, with the CONMEBOL team hosting the second leg.
Qualified teams
The following five teams from CONMEBOL qualified for the final tournament.