All available race results Jan la Grouw
| Date | Race | Rank |
| 20/08 | World Championships Road Race (Amateurs) | 9 |
Rider information for 1949
| Rank | 636 |
| Score | 37 |
| Name | Jan LA GROUW |
| Country | Netherlands |
| Team | Individual |
| Date | Race | Rank |
| Wyścig Pokoju / Závod Míru / Friedensfahrt | ||
| 30/04 | Stage 1 | 10 |
| 07/05 | Stage 7 | 5 |
| 10/05 | Stage 9 | 9 |
| 13/05 | Stage 12 | 10 |
| 13/05 | General Classification | 12 |
Rider information for 1952
| Rank | 645 |
| Score | 31 |
| Name | Jan LA GROUW |
| Country | Netherlands |
| Team | Individual |
| Date | Race | Rank |
| Ronde van Nederland | ||
| 02/05 | General Classification | 38 |
Rider information for 1954
| Rank | 1011 |
| Score | 5 |
| Name | Jan LA GROUW |
| Country | Netherlands |
| Team | Determeyer |