# 1990 Puerto Rico Open – Singles

Laura Gildemeister was the defending champion, but did not compete this year.
Jennifer Capriati won the title by defeating Zina Garrison 5–7, 6–4, 6–2 in the final.

## Seeds

* Zina Garrison (final)
* Jennifer Capriati (champion)
* Amy Frazier (first round)
* Helen Kelesi (second round)
* Raffaella Reggi (second round)
* Gigi Fernández (semifinals)
* Lori McNeil (second round)
* Ann Grossman (quarterfinals)

## Draw
### Key

* 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

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final | Final |
| 1 | Zina Garrison | 6 | 6 | | | | | |
| | Carrie Cunningham | 4 | 4 | | | | | |
| | Carrie Cunningham | 4 | 4 | 1 | Zina Garrison | 7 | 4 | 2 |
| | | | | 2 | Jennifer Capriati | 5 | 6 | 6 |
| 6 | Gigi Fernández | 2 | 1 | 2 | Jennifer Capriati | 5 | 6 | 6 |
| 2 | Jennifer Capriati | 6 | 6 | | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | Z Garrison | 6 | 7 | | | | | | | | | | | | | | | |
| | E Pampoulova | 3 | 5 | | 1 | Z Garrison | 7 | 6 | | | | | | | | | | |
| Q | S Smith | 4 | 6 | 7 | Q | S Smith | 5 | 1 | | | | | | | | | | |
| | L Ferrando | 6 | 3 | 5 | | | | | | 1 | Z Garrison | 7$^7$ | 3 | 6 | | | | |
| LL | L Corsato | 3 | 3 | | | | | | | 8 | A Grossman | 6$^4$ | 6 | 1 | | | | |
| Q | E Brioukhovets | 6 | 6 | | Q | E Brioukhovets | 1 | 6 | 6$^5$ | | | | | | | | | |
| | W White-Prausa | 4 | 5 | | 8 | A Grossman | 6 | 4 | 7$^7$ | | | | | | | | | |
| 8 | A Grossman | 6 | 7 | | | | | | | | | | | | 1 | Z Garrison | 6 | 6 |
| 3 | A Frazier | 6 | 1 | 4 | | | | | | | | | | | | C Cunningham | 4 | 4 |
| Q | E Reinach | 2 | 6 | 6 | Q | E Reinach | 6 | 5 | 1 | | | | | | | | | |
| | C Cunningham | 5 | | | | C Cunningham | 2 | 7 | 6 | | | | | | | | | |
| | P Hy | 1$^r$ | | | | | | | | | C Cunningham | 6 | 6 | | | | | |
| | F Labat | 6 | 6 | | | | | | | | F Labat | 2 | 3 | | | | | |
| | B Reinstadler | 4 | 3 | | | F Labat | 6 | 4 | 7$^7$ | | | | | | | | | |
| | L Harvey Wild | 5 | 2 | | 5 | R Reggi | 4 | 6 | 6$^4$ | | | | | | | | | |
| 5 | R Reggi | 7 | 6 | | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | G Fernández | 7$^7$ | 6 | | | | | | | | | | | | | | |
| | B Bowes | 6$^3$ | 3 | 6 | G Fernández | 6 | 7$^8$ | | | | | | | | | | |
| | N Provis | 6 | 6 | | N Provis | 4 | 6$^6$ | | | | | | | | | | |
| | B Fulco | 2 | 1 | | | | | | 6 | G Fernández | 6 | 4 | 6 | | | | |
| | A Coetzer | 2 | 2 | | | | | | | A Keller | 1 | 6 | 4 | | | | |
| | A Keller | 6 | 6 | | A Keller | 6 | 2 | 6 | | | | | | | | | |
| | C Benjamin | 2 | 2 | 4 | H Kelesi | 3 | 6 | 4 | | | | | | | | | |
| 4 | H Kelesi | 6 | 6 | | | | | | | | | | | 6 | G Fernández | 2 | 1 |
| 7 | L McNeil | 6 | 6 | | | | | | | | | | | 2 | J Capriati | 6 | 6 |
| | F Haumüller | 3 | 2 | 7 | L McNeil | 5 | 7$^7$ | 1 | | | | | | | | | |
| Q | M Strandlund | 6 | 6 | Q | M Strandlund | 7 | 6$^3$ | 6 | | | | | | | | | |
| | Ca MacGregor | 3 | 3 | | | | | | Q | M Strandlund | 1 | 4 | | | | | |
| | M McGrath | 7 | 6 | | | | | | 2 | J Capriati | 6 | 6 | | | | | |
| | N Medvedeva | 5 | 4 | | M McGrath | 3 | 2 | | | | | | | | | | |
| | A Strnadová | 0 | 6$^3$ | 2 | J Capriati | 6 | 6 | | | | | | | | | | |
| 2 | J Capriati | 6 | 7$^7$ | | | | | | | | | | | | | | |