# 1990 Belgian Indoor Championships – Singles

Henri Leconte was the champion of the event when it last took place, in 1988. He participated in 1990 but lost in the first round. Boris Becker won the title, defeating Carl-Uwe Steeb 7–5, 6–2, 6–2, in the final.

## Seeds

* Boris Becker (champion)
* Carl-Uwe Steeb (final)
* Emilio Sánchez (first round)
* Jakob Hlasek (second round)
* Ronald Agénor (quarterfinals)
* Magnus Gustafsson (semifinals)
* Paolo Canè (quarterfinals, retired)
* Goran Ivanišević (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 | Boris Becker | 6 | 7 | | | | | |
| 6 | Magnus Gustafsson | 4 | 6 | | | | | |
| 6 | Magnus Gustafsson | 4 | 6 | 1 | Boris Becker | 7 | 6 | 6 |
| | | | | 2 | Carl-Uwe Steeb | 5 | 2 | 2 |
| | Miloslav Mečíř | 2 | 3 | 2 | Carl-Uwe Steeb | 5 | 2 | 2 |
| 2 | Carl-Uwe Steeb | 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 | B Becker | 7$^7$ | 6 | | | | | | | | | | | | | | | |
| | K Nováček | 6$^4$ | 2 | | 1 | B Becker | 3 | 6 | 7$^7$ | | | | | | | | | |
| Q | A Boetsch | 3 | 4 | | | G Forget | 6 | 3 | 6$^4$ | | | | | | | | | |
| | G Forget | 6 | 6 | | | | | | | 1 | B Becker | 6 | 3 | | | | | |
| | J Aguilera | 6 | 6$^4$ | 6 | | | | | | | P Canè | 4 | 2$^r$ | | | | | |
| | M Střelba | 2 | 7$^7$ | 3 | | J Aguilera | 3 | 7$^7$ | 4 | | | | | | | | | |
| | O Camporese | 3 | 3 | | 7 | P Canè | 6 | 6$^0$ | 6 | | | | | | | | | |
| 7 | P Canè | 6 | 6 | | | | | | | | | | | | 1 | B Becker | 6 | 7$^7$ |
| 4 | J Hlasek | 6 | 6 | | | | | | | | | | | | 6 | M Gustafsson | 4 | 6$^4$ |
| | M Koevermans | 4 | 1 | | 4 | J Hlasek | 7 | 2 | 6$^9$ | | | | | | | | | |
| | A Volkov | 4 | 6$^3$ | | | J Svensson | 5 | 6 | 7$^{11}$ | | | | | | | | | |
| | J Svensson | 6 | 7$^7$ | | | | | | | | J Svensson | 7$^7$ | 6$^3$ | 3 | | | | |
| Q | T Nelson | 3 | 6 | 4 | | | | | | 6 | M Gustafsson | 6$^3$ | 7$^7$ | 6 | | | | |
| | A Mansdorf | 6 | 3 | 6 | | A Mansdorf | 4 | 4 | | | | | | | | | | |
| | J Gunnarsson | 2 | 2 | | 6 | M Gustafsson | 6 | 6 | | | | | | | | | | |
| 6 | M Gustafsson | 6 | 6 | | | | | | | | | | | | | | | |

### 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 5 | R Agénor | 6 | 6 | | | | | | | | | | | | | | | |
| | M Schapers | 4 | 4 | | 5 | R Agénor | 6 | 6 | | | | | | | | | | |
| WC | X Daufresne | 6 | 2 | 1 | WC | B Wuyts | 4 | 4 | | | | | | | | | | |
| WC | B Wuyts | 4 | 6 | 6 | | | | | | 5 | R Agénor | 3 | 2 | | | | | |
| | A Cherkasov | 6 | 6$^1$ | 2 | | | | | | | M Mečíř | 6 | 6 | | | | | |
| Q | A Rahunen | 4 | 7$^7$ | 6 | Q | A Rahunen | 6$^3$ | 4 | | | | | | | | | | |
| | M Mečíř | 6 | 3 | 6 | | M Mečíř | 7$^7$ | 6 | | | | | | | | | | |
| 3 | E Sánchez | 4 | 6 | 4 | | | | | | | | | | | | M Mečíř | 2 | 3 |
| 8 | G Ivanišević | 6 | 2 | 6 | | | | | | | | | | | 2 | C-U Steeb | 6 | 6 |
| | J Wöhrmann | 4 | 6 | 3 | 8 | G Ivanišević | 6 | 6$^2$ | 6 | | | | | | | | | |
| | G Prpić | 6 | 5 | 6 | | G Prpić | 3 | 7$^7$ | 2 | | | | | | | | | |
| WC | H Leconte | 3 | 7 | 1 | | | | | | 8 | G Ivanišević | 3 | 6 | 4 | | | | |
| Q | T Högstedt | 6 | 6 | | | | | | | 2 | C-U Steeb | 6 | 3 | 6 | | | | |
| | M Rosset | 4 | 2 | | Q | T Högstedt | 6$^1$ | 6 | 2 | | | | | | | | | |
| | E Jelen | 3 | 6$^2$ | | 2 | C-U Steeb | 7$^7$ | 4 | 6 | | | | | | | | | |
| 2 | C-U Steeb | 6 | 7$^7$ | | | | | | | | | | | | | | | |