Record: 65-52, .556 W-L% (4th of 11) (Schedule and Results)
SRS: 5.82 (3rd of 11) ▪ SOS: 4.64 (2nd of 11)
Conference Champion: UCLA
Ranked in Preseason AP Poll: 4 (Arizona, Arizona State, UCLA and Washington)
Ranked in Final AP Poll: 2 (Arizona and UCLA)
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
|---|---|---|---|---|---|---|---|---|
| 1 | Sep 5, 1998 | Sat | (18) Washington | 42 | @ | (8) Arizona State | 38 | |
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 2 | Sep 12, 1998 | Sat | (21) Arizona | 31 | @ | Stanford | 14 | |
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 3 | Sep 19, 1998 | Sat | (18) Southern California | 40 | Oregon State | 20 | ||
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 4 | Sep 26, 1998 | Sat | Arizona State | 24 | Oregon State | 3 | ||
| 5 | Sep 26, 1998 | Sat | California | 24 | Washington State | 14 | ||
| 6 | Sep 26, 1998 | Sat | (20) Oregon | 63 | Stanford | 28 | ||
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 7 | Oct 3, 1998 | Sat | (14) Arizona | 31 | @ | (20) Washington | 28 | |
| 8 | Oct 3, 1998 | Sat | (21) Southern California | 35 | Arizona State | 24 | ||
| 9 | Oct 3, 1998 | Sat | (4) UCLA | 49 | Washington State | 17 | ||
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 10 | Oct 10, 1998 | Sat | California | 32 | @ | (19) Southern California | 31 | |
| 11 | Oct 10, 1998 | Sat | (15) Oregon | 51 | @ | Washington State | 29 | |
| 12 | Oct 10, 1998 | Sat | Oregon State | 30 | @ | Stanford | 23 | |
| 13 | Oct 10, 1998 | Sat | (3) UCLA | 52 | @ | (10) Arizona | 28 | |
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 14 | Oct 17, 1998 | Sat | (16) Arizona | 28 | @ | Oregon State | 7 | |
| 15 | Oct 17, 1998 | Sat | Southern California | 42 | @ | Washington State | 14 | |
| 16 | Oct 17, 1998 | Sat | (2) UCLA | 41 | (11) Oregon | 38 | ||
| 17 | Oct 17, 1998 | Sat | Washington | 21 | California | 13 | ||
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 18 | Oct 22, 1998 | Thu | Arizona State | 44 | Stanford | 38 | ||
| 19 | Oct 24, 1998 | Sat | (12) Oregon | 17 | Southern California | 13 | ||
| 20 | Oct 24, 1998 | Sat | (2) UCLA | 28 | @ | California | 16 | |
| 21 | Oct 24, 1998 | Sat | Washington | 35 | Oregon State | 34 | ||
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 22 | Oct 31, 1998 | Sat | (13) Arizona | 38 | (12) Oregon | 3 | ||
| 23 | Oct 31, 1998 | Sat | Arizona State | 38 | @ | Washington State | 28 | |
| 24 | Oct 31, 1998 | Sat | California | 20 | @ | Oregon State | 19 | |
| 25 | Oct 31, 1998 | Sat | Southern California | 33 | Washington | 10 | ||
| 26 | Oct 31, 1998 | Sat | (2) UCLA | 28 | Stanford | 24 | ||
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 27 | Nov 7, 1998 | Sat | (10) Arizona | 41 | Washington State | 7 | ||
| 28 | Nov 7, 1998 | Sat | Arizona State | 55 | California | 22 | ||
| 29 | Nov 7, 1998 | Sat | (21) Oregon | 27 | Washington | 22 | ||
| 30 | Nov 7, 1998 | Sat | Southern California | 34 | @ | Stanford | 9 | |
| 31 | Nov 7, 1998 | Sat | (3) UCLA | 41 | @ | Oregon State | 34 | |
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 32 | Nov 14, 1998 | Sat | (9) Arizona | 27 | @ | California | 23 | |
| 33 | Nov 14, 1998 | Sat | (20) Oregon | 51 | Arizona State | 19 | ||
| 34 | Nov 14, 1998 | Sat | Stanford | 38 | Washington State | 28 | ||
| 35 | Nov 14, 1998 | Sat | (3) UCLA | 36 | @ | Washington | 24 | |
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 36 | Nov 21, 1998 | Sat | Oregon State | 44 | (15) Oregon | 41 | ||
| 37 | Nov 21, 1998 | Sat | Stanford | 10 | @ | California | 3 | |
| 38 | Nov 21, 1998 | Sat | (3) UCLA | 34 | Southern California | 17 | ||
| 39 | Nov 21, 1998 | Sat | Washington | 16 | @ | Washington State | 9 | |
| Rk | Date | Day | Winner/Tie | Pts | Loser/Tie | Pts | Notes | |
| 40 | Nov 27, 1998 | Fri | (7) Arizona | 50 | Arizona State | 42 |