|| Marquis || Fuentes || 39,007 || 20–13 |- style="background-color:#bbffbb" | 34 || May 9 || Rockies || 4–2 || Wainwright || Mesa || Isringhausen || 40,375 || 21–13 |- style="background-color:#bbffbb" | 35 || May 10 || Rockies || 7–4 || Suppan || B. Kim || Isringhausen || 39,108 || 22–13 |- style="background-color:#bbffbb" | 36 || May 12 || Diamondbacks || 5–3 || Mulder || Cruz || Isringhausen || 41,085 || 23–13 |- style="background-color:#bbffbb" | 37 || May 13 || Diamondbacks || 9–1 || Marquis || Vargas || || 40,585 || 24–13 |- style="background-color:#ffbbbb" | 38 || May 14 || Diamondbacks || 6–7 || Vizcaino || Wainwright || Valverde || 40,891|| 24–14 |- style="background-color:#ffbbbb" | 39 || May 16 || Mets || 3–8 || Glavine || Suppan || || 39,616 || 24–15 |- style="background-color:#bbffbb" | 40 || May 17 || Mets || 1–0 || Mulder || Trachsel || Isringhausen || 40,573 || 25–15 |- style="background-color:#bbffbb" | 41 || May 18 || Mets || 6–3 || Marquis || Lima || Isringhausen || 40,573 || 26–15 |- style="background-color:#bbffbb" | 42 || May 19 || @ Royals || 9–6 || Carpenter || Redman || Wainwright || 33,045 || 27–15 |- style="background-color:#bbffbb" | 43 || May 20 || @ Royals || 4–2 || Reyes || Bautista || Isringhausen || 40,516 || 28–15 |- style="background-color:#bbffbb" | 44 || May 21 || @ Royals || 10–3 || Suppan || Elarton || || 30,266 || 29–15 |- style="background-color:#ffbbbb" | 45 || May 22 || @ Giants || 2–9 || Wright || Mulder || || 38,133 || 29–16 |- style="background-color:#bbffbb" | 46 || May 23 || @ Giants || 8–5 || Marquis || Morris || Isringhausen || 37,986 || 30–16 |- style="background-color:#bbffbb" | 47 || May 24 || @ Giants || 10–4 || Wainwright || Lowry || || 37,752 || 31–16 |- style="background-color:#ffbbbb" | 48 || May 26 || @ Padres || 1–7 || Hensley || Suppan || || 40,075 || 31–17 |- style="background-color:#bbffbb" | 49 || May 27 || @ Padres || 4–3 || Ponson || Park || Isringhausen || 32,722 || 32–17 |- style="background-color:#ffbbbb" | 50 || May 28 || @ Padres || 8–10 || Peavy|| Mulder || Hoffman || 38,145 || 32–18 |- style="background-color:#bbffbb" | 51 || May 29 || Astros || 3–1 || Marquis || Miller || Isringhausen || 45,509 || 33–18 |- style="background-color:#ffbbbb" | 52 || May 30 || Astros || 3–6 ||