Roberto Quiroz and Caio Zampieri were the defending champions but only Quiroz chose to defend his title, partnering Yannick Hanfmann. Quiroz lost in the quarterfinals to Jay Clarke and Kevin Krawietz.
| Doubles | |
|---|---|
| 2018 San Luis Open Challenger Tour | |
| Champions |  Marcelo Arévalo Miguel Ángel Reyes-Varela |
| Runners-up |  Jay Clarke Kevin Krawietz |
| Score | 6–1, 6–4 |
Marcelo Arévalo and Miguel Ángel Reyes-Varela won the title after defeating Clarke and Krawietz 6–1, 6–4 in the final.
Seeds edit
Austin Krajicek / Jackson Withrow (semifinals)
Marcelo Arévalo / 
Miguel Ángel Reyes-Varela (champions)
Franco Agamenone / 
Sergio Galdós (quarterfinals)- Evan King / Nathan Pasha (first round)
Draw edit
Key edit
- Q = Qualifier
- WC = Wild card
- LL = Lucky loser
- Alt = Alternate
- SE = Special exempt
- PR = Protected ranking
- ITF = ITF entry
- JE = Junior exempt
- w/o = Walkover
- r = Retired
- d = Defaulted
- SR = Special ranking
| First round | Quarterfinals | Semifinals | Final | ||||||||||||||||||||||||
| 1 |  A Krajicek J Withrow
| 6 | 6 | ||||||||||||||||||||||||
| Alt |  P Sakamoto JP Sorgi
| 4 | 4 | 1 | A Krajicek J Withrow
| w/o | |||||||||||||||||||||
 P Krstin D Muñoz de la Nava
| 7 | 6 | P Krstin D Muñoz de la Nava
| ||||||||||||||||||||||||
 A Collarini F Coria
| 5 | 2 | 1 | A Krajicek J Withrow
| 3 | 4 | |||||||||||||||||||||
| 4 | E King N Pasha
| 64 | 77 | [6] | J Clarke K Krawietz
| 6 | 6 | ||||||||||||||||||||
Y Hanfmann R Quiroz
| 77 | 63 | [10] | Y Hanfmann R Quiroz
| 65 | 6 | [5] | ||||||||||||||||||||
| WC |  A Gómez T Hank
| 4 | 1 | J Clarke K Krawietz
| 77 | 3 | [10] | ||||||||||||||||||||
| J Clarke K Krawietz
| 6 | 6 | J Clarke K Krawietz
| 1 | 4 | ||||||||||||||||||||||
 B Arias F Zeballos
| 4 | 77 | [10] | 2 | M Arévalo MÁ Reyes-Varela
| 6 | 6 | ||||||||||||||||||||
| F Argüello F Bagnis
| 6 | 65 | [4] | B Arias F Zeballos
| 6 | 6 | |||||||||||||||||||||
| WC | E Gómez L Gómez
| 1 | 4 | 3 | F Agamenone S Galdós
| 3 | 4 | ||||||||||||||||||||
| 3 | F Agamenone S Galdós
| 6 | 6 | B Arias F Zeballos
| 4 | 4 | |||||||||||||||||||||
| WC | G López Villaseñor M Sánchez
| 77 | 6 | 2 | M Arévalo MÁ Reyes-Varela
| 6 | 6 | ||||||||||||||||||||
 LD Martínez R Statham
| 61 | 4 | WC | G López Villaseñor M Sánchez
| 5 | 64 | |||||||||||||||||||||
| M Krueger A Sarkissian
| 1 | 3 | 2 | M Arévalo MÁ Reyes-Varela
| 7 | 77 | |||||||||||||||||||||
| 2 | M Arévalo MÁ Reyes-Varela
| 6 | 6 | ||||||||||||||||||||||||