2018 Challenger ATP Cachantún Cup – Doubles

Marcelo Tomás Barrios Vera and Nicolás Jarry were the defending champions but only Barrios Vera chose to defend his title, partnering José Hernández-Fernández. Barrios Vera lost in the semifinals to Romain Arneodo and Jonathan Eysseric.

Arneodo and Eysseric won the title after defeating Guido Andreozzi and Guillermo Durán 7–6(7–4), 1–6, [12–10] in the final.

Seeds
• # 🇦🇷 Máximo González / 🇦🇷 Andrés Molteni (semifinals)

• # Romain Arneodo / 🇫🇷 Jonathan Eysseric (champions)

• # 🇦🇷 Guido Andreozzi / 🇦🇷 Guillermo Durán (final)

• # 🇦🇷 Franco Agamenone / 🇵🇪 Sergio Galdós (quarterfinals)