1998 Seattle Mariners season Game log May

| Date_ | Opponent | Score | Loss | Attendance | Record |
|---|---|---|---|---|---|
| May 13 | @ Detroit Tigers | 5-8 | Cloude (3-2) | 10766 | 19-19 |
| May 14 | @ Chicago White Sox | 3-5 | Johnson (3-2) | 15007 | 19-20 |
| May 15 | @ Chicago White Sox | 3-6 | Swift (2-3) | 16127 | 19-21 |
| May 16 | @ Toronto Blue Jays | 8-1 | Guzman (1-6) | 31121 | 20-21 |
| May 17 | @ Toronto Blue Jays | 3-4 | Slocumb (1-3) | 28111 | 20-22 |
| May 18 | @ Toronto Blue Jays | 9-4 | Clemens (4-5) | 28125 | 21-22 |
| May 19 | @ Texas Rangers | 4-10 | Johnson (3-3) | 37258 | 21-23 |
| May 20 | @ Texas Rangers | 7-8 | Timlin (1-3) | 29454 | 21-24 |
| May 21 | @ Texas Rangers | 8-9 | Ayala (0-3) | 34613 | 21-25 |
| May 22 | Tampa Bay Devil Rays | 2-5 | Moyer (2-5) | 29522 | 21-26 |