Two medal events were scheduled to be contested: a men's and women's tournament. A total of 168 athletes (78 athletes–6 teams for men and 91 athletes–7 teams for women) competed in the events. Both tournaments were open competitions without age restrictions.[1]
The gold and silver medalists teams in each tournament qualified for the 2023 Pan American Gameswater polo competitions, plus Chile which qualified automatically as the 2023 Pan American Games hosts.[2]
Argentina and Brazil were the defending champions of the South American Games men's and women's water polo events. Argentina had won the men's tournament in the last edition in Cochabamba 2018 while Brazil had won the women's tournament in the Medellín 2010 edition (women's event was not held in Santiago 2014 nor Cochabamba 2018).
Brazil won the gold medal in both men's and women's events.[3]
A total of 8 ODESUR nations registered teams for the water polo events. Each nation was able to enter a maximum of 26 athletes (one team of 13 players per gender).[1] Argentina, Brazil, Chile, Colombia and hosts Paraguay participated in both men's and women's tournament. Uruguay participated in the men's tournament, while Peru and Venezuela participated in the women's tournament.