All available race results Guillaume Nyssen
| Date | Race | Rank |
| 19/04 | Bruxelles - Liège | 3 |
| 01/06 | Tour de Belgique en ligne | 1 |
Rider information for 1914
| Rank | 260 |
| Score | 37 |
| Name | Guillaume NYSSEN |
| Country | Belgium |
| Team | Individual |
| Date | Race | Rank |
| 11/04 | Bruxelles - Liège | 4 |
| 26/04 | Vilvoorde - De IJzer - Vilvoorde | 17 |
Rider information for 1920
| Rank | 360 |
| Score | 21 |
| Name | Guillaume NYSSEN |
| Country | Belgium |
| Team | Individual |
| Date | Race | Rank |
| Tour de Belgique | ||
| 01/05 | Stage 1 | 17 |
| 03/05 | Stage 2 | 19 |
| 05/05 | Stage 3 | 17 |
| 07/05 | Stage 4 | 8 |
| 08/05 | Stage 5 | 7 |
| 08/05 | General Classification | 9 |
| 29/05 | Liège - Bastogne - Liège | 5 |
Rider information for 1921
| Rank | 82 |
| Score | 331 |
| Name | Guillaume NYSSEN |
| Country | Belgium |
| Team | Individual |
| Date | Race | Rank |
| Tour de France | ||
| 25/06 | Stage 1 | 13 |
Rider information for 1922
| Rank | 286 |
| Score | 54 |
| Name | Guillaume NYSSEN |
| Country | Belgium |
| Team | Individual |