2003 Chicago Cubs season Game log May

| Date_ | Opponent | Score | Loss | Attendance | Record |
|---|---|---|---|---|---|
| May 11 | Cardinals | Postponed (rain) Rescheduled for September 2 | Postponed (rain) Rescheduled for September 2 | Postponed (rain) Rescheduled for September 2 | Postponed (rain) Rescheduled for September 2 |
| May 12 | @ Brewers | 11–5 | Rusch (1–7) | 19106 | 21–16 |
| May 13 | @ Brewers | 7–2 | Quevedo (0–1) | 18454 | 22–16 |
| May 14 | @ Brewers | 6–1 | Kinney (2–3) | 27566 | 23–16 |
| May 15 | @ Brewers | 4 – 2 (17) | Kieschnick (0–1) | 31624 | 24–16 |
| May 16 | @ Cardinals | 7–4 | Clement (2–5) | 42589 | 24–17 |
| May 17 | @ Cardinals | 2–1 | Kline (1–4) | 45385 | 25–17 |
| May 18 | @ Cardinals | 6–3 | Cruz (1–2) | 45773 | 25–18 |
| May 19 | @ Cardinals | 2–0 | Zambrano (4–4) | 46734 | 25–19 |