| Administrator: | Test and County Cricket Board |
| Cricket Format: | Limited overs cricket(40 overs per innings) |
| Tournament Format: | League |
| Champions: | Derbyshire |
| Count: | 1 |
| Participants: | 17 |
| Matches: | 136 |
| Most Runs: | 902 Jimmy Cook (Somerset) |
| Most Wickets: | 31 Waqar Younis (Surrey) |
| Previous Year: | 1989 |
| Previous Tournament: | 1989 Refuge Assurance League |
| Next Year: | 1991 |
| Next Tournament: | 1991 Refuge Assurance League |
The 1990 Refuge Assurance League was the twenty-second competing of what was generally known as the Sunday League. The competition was won for the first time by Derbyshire County Cricket Club.
| width=200 | Team | width=20 | Pld | width=20 | W | width=20 | T | width=20 | L | width=20 | N/R | width=20 | A | width=20 | Pts | width=60 | Rp100 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Derbyshire (C) | 16 | 12 | 0 | 3 | 1 | 0 | 50 | 87.354 | |||||||||
| 16 | 11 | 0 | 3 | 1 | 1 | 48 | 100.186 | ||||||||||
| 16 | 10 | 0 | 5 | 1 | 0 | 42 | 95.401 | ||||||||||
| 16 | 10 | 0 | 5 | 1 | 0 | 42 | 89.313 | ||||||||||
| 16 | 9 | 0 | 5 | 2 | 0 | 40 | 88.828 | ||||||||||
| 16 | 9 | 0 | 6 | 0 | 1 | 38 | 90.393 | ||||||||||
| 16 | 9 | 0 | 6 | 0 | 1 | 38 | 83.607 | ||||||||||
| 16 | 7 | 0 | 7 | 2 | 0 | 32 | 87.808 | ||||||||||
| 16 | 8 | 0 | 8 | 0 | 0 | 32 | 91.255 | ||||||||||
| 16 | 7 | 0 | 8 | 0 | 1 | 30 | 85.950 | ||||||||||
| 16 | 7 | 0 | 8 | 1 | 0 | 30 | 84.964 | ||||||||||
| 16 | 6 | 0 | 9 | 0 | 1 | 26 | 90.570 | ||||||||||
| 16 | 5 | 0 | 9 | 0 | 2 | 24 | 85.906 | ||||||||||
| 16 | 5 | 0 | 10 | 1 | 0 | 22 | 80.695 | ||||||||||
| 16 | 4 | 0 | 11 | 0 | 1 | 18 | 84.209 | ||||||||||
| 16 | 4 | 0 | 11 | 1 | 0 | 18 | 76.592 | ||||||||||
| 16 | 3 | 0 | 12 | 1 | 0 | 14 | 83.411 | ||||||||||
| Team marked | |||||||||||||||||