# 1991 Geneva Open – Singles

Horst Skoff was the defending champion, but lost in the final this year.
Thomas Muster won the title, defeating Skoff 6–2, 6–4 in the final.

## Seeds

* Sergi Bruguera (quarterfinals)
* Andrei Cherkasov (first round)
* Goran Prpić (second round)
* Horst Skoff (final)
* Alberto Mancini (second round)
* Marc Rosset (first round)
* Guillermo Pérez Roldán (second round)
* Omar Camporese (first 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 |
| | Thomas Muster | 7$^7$ | 7$^7$ | | | | |
| WC | Andrei Medvedev | 6$^3$ | 6$^5$ | | | | |
| WC | Andrei Medvedev | 6$^3$ | 6$^5$ | | Thomas Muster | 6 | 6 |
| | | | | 4 | Horst Skoff | 2 | 4 |
| 4 | Horst Skoff | 7$^{10}$ | 6 | 4 | Horst Skoff | 2 | 4 |
| | Jordi Arrese | 6$^8$ | 2 | | | | |

### 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 | S Bruguera | 6 | 6 | | | | | | | | | | | | | | | |
| | B Wuyts | 3 | 2 | | 1 | S Bruguera | 7$^8$ | 1 | 6 | | | | | | | | | |
| WC | C Mezzadri | 6 | 7 | | WC | C Mezzadri | 6$^6$ | 6 | 1 | | | | | | | | | |
| WC | T Tulasne | 3 | 5 | | | | | | | 1 | S Bruguera | 6 | 4 | 4 | | | | |
| | T Muster | 6 | 7 | | | | | | | | T Muster | 4 | 6 | 6 | | | | |
| | M Vajda | 3 | 5 | | | T Muster | 4 | 6 | 6 | | | | | | | | | |
| | M Filippini | 6$^1$ | 3 | | 7 | G Pérez Roldán | 6 | 1 | 2 | | | | | | | | | |
| 7 | G Pérez Roldán | 7$^7$ | 6 | | | | | | | | | | | | | T Muster | 7$^7$ | 7$^7$ |
| 3 | G Prpić | 4 | 6 | 6 | | | | | | | | | | | WC | A Medvedev | 6$^3$ | 6$^5$ |
| | G Bloom | 6 | 4 | 4 | 3 | G Prpić | 7$^9$ | 0 | 5 | | | | | | | | | |
| | R Furlan | 4 | 5 | | Q | C Miniussi | 6$^7$ | 6 | 7 | | | | | | | | | |
| Q | C Miniussi | 6 | 7 | | | | | | | Q | C Miniussi | 4 | 7 | 5 | | | | |
| | J Gunnarsson | 3 | 3 | | | | | | | WC | A Medvedev | 6 | 5 | 7 | | | | |
| | E Masso | 6 | 6 | | | E Masso | 7 | 6$^3$ | 1 | | | | | | | | | |
| WC | A Medvedev | 6 | 6 | | WC | A Medvedev | 5 | 7$^7$ | 6 | | | | | | | | | |
| 6 | M Rosset | 2 | 1 | | | | | | | | | | | | | | | |

### 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 | A Mancini | 6 | 7$^7$ | | | | | | | | | | | | | | | |
| | L Mattar | 3 | 6$^5$ | | 5 | A Mancini | 1 | 6 | 4 | | | | | | | | | |
| | H de la Peña | 7$^7$ | 7$^7$ | | | H de la Peña | 6 | 3 | 6 | | | | | | | | | |
| | F Davín | 6$^5$ | 6$^4$ | | | | | | | | H de la Peña | 6$^3$ | 6 | 1 | | | | |
| | P Baur | 6 | 6$^5$ | 5 | | | | | | 4 | H Skoff | 7$^7$ | 4 | 6 | | | | |
| Q | M Merz | 3 | 7$^7$ | 7 | Q | M Merz | 2 | 0 | | | | | | | | | | |
| | G López | 2 | 0 | | 4 | H Skoff | 6 | 6 | | | | | | | | | | |
| 4 | H Skoff | 6 | 6 | | | | | | | | | | | | 4 | H Skoff | 7$^{10}$ | 6 |
| 8 | O Camporese | 3 | 4 | | | | | | | | | | | | | J Arrese | 6$^8$ | 2 |
| Q | C Arriens | 6 | 6 | | Q | C Arriens | 5 | 7 | 5 | | | | | | | | | |
| | J Oncins | 6 | 7 | | | J Oncins | 7 | 5 | 7 | | | | | | | | | |
| Q | J Gisbert-Schultze | 4 | 5 | | | | | | | | J Oncins | 6 | 4 | 5 | | | | |
| | V Paloheimo | 7$^7$ | 4 | 6 | | | | | | | J Arrese | 4 | 6 | 7 | | | | |
| | R Agénor | 6$^5$ | 6 | 4 | | V Paloheimo | 2 | 6 | 5 | | | | | | | | | |
| | J Arrese | 6 | 4 | 6 | | J Arrese | 6 | 3 | 7 | | | | | | | | | |
| 2 | A Cherkasov | 4 | 6 | 1 | | | | | | | | | | | | | | |