1998 Seattle Mariners season Game log May

| Date_ | Opponent | Score | Loss | Attendance | Record |
|---|---|---|---|---|---|
| May 1 | Detroit Tigers | 3-17 | Swift (2-1) | 28827 | 12-16 |
| May 2 | Detroit Tigers | 4-0 | Thompson (1-4) | 48630 | 13-16 |
| May 3 | Detroit Tigers | 10-6 | Castillo (0-1) | 44488 | 14-16 |
| May 5 | Chicago White Sox | 8-1 | Eyre (1-4) | 22760 | 15-16 |
| May 6 | Chicago White Sox | 10-9 | Castillo (0-2) | 21243 | 16-16 |
| May 7 | Toronto Blue Jays | 0-6 | Moyer (2-4) | 24129 | 16-17 |
| May 8 | Toronto Blue Jays | 8-3 | Williams (3-2) | 29920 | 17-17 |
| May 9 | Toronto Blue Jays | 1-4 | Swift (2-2) | 49851 | 17-18 |
| May 10 | Toronto Blue Jays | 3-1 | Guzman (1-5) | 39249 | 18-18 |
| May 12 | @ Detroit Tigers | 4-2 | Thompson (2-5) | 11659 | 19-18 |