1991 AMA Pro Motocross Championship Unadilla Motocross: 500MX Results
October 13, 1991
- Monster Energy AMA Supercross Championship
- AMA Pro Motocross Championship
- SuperMotocross World Championship
- FIM Motocross World Championship
- Progressive GNCC Racing
- Motocross of Nations
- FIM World Supercross Championship
- Australian Supercross Championship
- Women's Motocross Championship
- Monster Energy Cup
500MX Results
| Rider | Hometown | Motos | Bike | |
|---|---|---|---|---|
| 1 | Jeff Ward | Mission Viejo, CA | 1 - 1 | Kawasaki |
| 2 | | France | 2 - 5 | Honda |
| 3 | | Charlotte, NC | 6 - 3 | Yamaha |
| 4 | | Santee, CA | 4 - 6 | KTM |
| 5 | | Litchfield Park, AZ | 3 - 8 | Kawasaki |
| 6 | | Sherwood, MI | 13 - 2 | Honda |
| 7 | | Hudsonville, MI | 11 - 4 | Kawasaki |
| 8 | | Wappingers Falls, NY | 8 - 7 | Honda |
| 9 | Ron Lechien | El Cajon, CA | 7 - 10 | Kawasaki |
| 10 | | Capistrano Beach, CA | 9 - 9 | Kawasaki |
| 11 | | Hopedale, OH | 10 - 12 | Kawasaki |
| 12 | | Costa Mesa, CA | 5 - 24 | Yamaha |
| 13 | | Earlville, NY | 17 - 14 | Yamaha |
| 14 | | Ketchum, ID | 14 - 17 | Honda |
| 15 | | North Canton, OH | 23 - 11 | Kawasaki |
| 16 | | Pembroke, MA | 15 - 18 | KTM |
| 17 | | Vineland, NJ | 12 - 27 | Honda |
| 18 | | Drummondville, QC | 21 - 13 | Honda |
| 19 | | Tallahassee, FL | 27 - 15 | Honda |
| 20 | | Sedalia, CO | 25 - 16 | Yamaha |
| 21 | | Pontiac, MI | 16 - 38 | KTM |
| 22 | | Colts Neck, NJ | 18 - 20 | Suzuki |
| 23 | | Barrie, ON | 22 - 19 | Honda |
| 24 | | Oshama, ON | 19 - 26 | KTM |
| 25 | | Worth, IL | 20 - 24 | Honda |


