# 1990 Citibank Open – Singles

Martín Jaite was the defending champion, but lost in the first round to Mark Koevermans.
Mats Wilander won the title by defeating Marcelo Filippini 6–1, 6–2 in the final. It was the 33rd and final singles title for Wilander in his career.

## Seeds

* Juan Aguilera (first round)
* Martín Jaite (first round)
* Karel Nováček (second round)
* Franco Davín (first round)
* Mats Wilander (champion)
* Luiz Mattar (second round)
* Marcelo Filippini (final)
* Jean-Philippe Fleurian (second round)

## 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 |
| 7 | Marcelo Filippini | 7 | 6 | | | | |
| | Tomás Carbonell | 6 | 4 | | | | |
| | Tomás Carbonell | 6 | 4 | 7 | Marcelo Filippini | 1 | 2 |
| | | | | 5/WC | Mats Wilander | 6 | 6 |
| 5/WC | Mats Wilander | 6 | 6 | 5/WC | Mats Wilander | 6 | 6 |
| | Mark Koevermans | 4 | 3 | | | | |

### 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 | J Aguilera | 6 | 3 | | | | | | | | | | | | | | | |
| WC | D Marcelino | 7 | 6 | | WC | D Marcelino | 6 | 1 | 2 | | | | | | | | | |
| | N Marques | 6 | 6 | 6 | | N Marques | 3 | 6 | 6 | | | | | | | | | |
| | A Mancini | 0 | 7 | 4 | | | | | | | N Marques | 3 | 6 | 6 | | | | |
| | M Wostenholme | 2 | 2 | | | | | | | 7 | M Filippini | 6 | 3 | 7 | | | | |
| | J Yzaga | 6 | 6 | | | J Yzaga | 2 | 2 | | | | | | | | | | |
| Q | T Anzari | 2 | 3 | | 7 | M Filippini | 6 | 6 | | | | | | | | | | |
| 7 | M Filippini | 6 | 6 | | | | | | | | | | | | 7 | M Filippini | 7 | 6 |
| 4 | F Davín | 6 | 0 | | | | | | | | | | | | | T Carbonell | 6 | 4 |
| | T Carbonell | 7 | 6 | | | T Carbonell | 4 | 6 | 6 | | | | | | | | | |
| | P Arraya | 7 | 3 | 5 | | JF Altur | 6 | 1 | 2 | | | | | | | | | |
| | JF Altur | 6 | 6 | 7 | | | | | | | T Carbonell | 6 | 7 | | | | | |
| | C Motta | 3 | 7 | 6 | | | | | | | C Motta | 3 | 5 | | | | | |
| Q | F Roese | 6 | 6 | 4 | | C Motta | 6 | 2 | 7 | | | | | | | | | |
| | R Azar | 3 | 6 | 5 | 6 | L Mattar | 1 | 6 | 5 | | | | | | | | | |
| 6 | L Mattar | 6 | 4 | 7 | | | | | | | | | | | | | | |

### Bottom 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 | Semifinals | Semifinals | Semifinals | Semifinals |
| 5/WC | M Wilander | 6 | 6 | | | | | | | | | | | | | | |
| | T Wilkison | 2 | 2 | | 5/WC | M Wilander | 6 | 6 | | | | | | | | | |
| | J Cunha e Silva | 2 | 6 | 6 | | J Cunha e Silva | 2 | 2 | | | | | | | | | |
| | H de la Peña | 6 | 3 | 4 | | | | | | 5/WC | M Wilander | 6 | 6 | | | | |
| | D Pérez | 7 | 3 | 6 | | | | | | | A Sznajder | 1 | 0 | | | | |
| | A Sznajder | 6 | 6 | 7 | | A Sznajder | 6 | 6 | | | | | | | | | |
| | C Garner | 1 | 4 | | 3 | K Nováček | 4 | 3 | | | | | | | | | |
| 3 | K Nováček | 6 | 6 | | | | | | | | | | | 5/WC | M Wilander | 6 | 6 |
| 8 | JP Fleurian | 4 | 6 | 6 | | | | | | | | | | | M Koevermans | 4 | 3 |
| WC | J Oncins | 6 | 1 | 1 | 8 | JP Fleurian | 3 | 3 | | | | | | | | | |
| Q | T Martin | 5 | 6 | | Q | M Ruah | 6 | 6 | | | | | | | | | |
| Q | M Ruah | 7 | 7 | | | | | | | Q | M Ruah | 6 | 3 | | | | |
| | C Costa | 6 | 3 | 2 | | | | | | | M Koevermans | 7 | 6 | | | | |
| | B Wuyts | 2 | 6 | 6 | | B Wuyts | 6 | 3 | 5 | | | | | | | | |
| | M Koevermans | 6 | 6 | 6 | | M Koevermans | 3 | 6 | 7 | | | | | | | | |
| 2 | M Jaite | 3 | 7 | 2 | | | | | | | | | | | | | |