[3] The draw of the tournament was held on 28 February 2018, 12:00 ART (UTC−3), at the Estadio Aldo Cantoni in San Juan.

The hosts Argentina and the defending champions Venezuela were seeded into Groups A and B respectively, while the remaining teams were placed into four "pairing pots" according to their results in the 2016 South American Under-17 Women's Football Championship: Brazil–Paraguay, Colombia–Uruguay, Chile–Ecuador, Peru–Bolivia.

If tied on points, tiebreakers are applied in the following order (Regulations Article 18.1):[6] The top two teams of each group advance to the final stage.

On 11 March 2018, the scheduled Group A match between Argentina and Ecuador was not played as players from several teams showed symptoms for food poisoning.

If tied on points, tiebreakers are applied in the following order, taking into account only matches in the final stage (Regulations Article 18.2):[6] The following three teams from CONMEBOL qualified for the 2018 FIFA U-17 Women's World Cup, including Uruguay which qualified as hosts.