31,777 || 8–12 |- style="background:#fbb" | 21 || May 11 || @ Dodgers || 3–4 (10) || Carl Erskine (2–0) || Howie Fox (0–4) || None || 9,104 || 8–13 |- style="background:#bbb" | – || May 12 || @ Dodgers || colspan=6 | Postponed (cold, wet grounds); Makeup: July 2 as a traditional double-header |- style="background:#bfb" | 22 || May 13 || Cubs || 6–0 || Curt Simmons (2–1) || Joe Hatten (2–2) || None || 5,702 || 9–13 |- style="background:#bfb" | 23 || May 14 || Cubs || 9–2 || Russ Meyer (1–4) || Bob Kelly (1–3) || None || 3,212 || 10–13 |- style="background:#bfb" | 24 || May 15 || Reds || 5–1 || Robin Roberts (6–1) || Ewell Blackwell (1–5) || None || 14,752 || 11–13 |- style="background:#bfb" | 25 || May 16 || Reds || 3–2 (10) || Ken Heintzelman (1–0) || Herm Wehmeier (3–2) || None || 19,313 || 12–13 |- style="background:#fbb" | 26 || May 17 || Reds || 3–7 || Frank Hiller (4–2) || Howie Fox (0–5) || None || 5,285 || 12–14 |- style="background:#fbb" | 27 || May 18 || Cardinals || 3–4 || Gerry Staley (7–1) || Russ Meyer (1–5) || Al Brazle (6) || 12,380 || 12–15 |- style="background:#bbb" | – || May 19 || Cardinals || colspan=6 | Postponed (rain); Makeup: June 17 as a traditional double-header |- style="background:#bbb" | – || May 20 || Pirates || colspan=6 | Postponed (rain); Makeup: June 16 |- style="background:#bfb" | 28 || May 21 || Pirates || 7–3 || Robin Roberts (7–1) || Murry Dickson (1–7) || None || 6,202 || 13–15 |- style="background:#bfb" | 29 || May 22 || Pirates || 6–0 || Curt Simmons (3–1) || Red Munger (0–2) || None || 3,065 || 14–15 |- style="background:#fbb" | 30 || May 23 || Dodgers || 1–5 || Ben Wade (3–1) || Karl Drews (1–3) || None || 30,323 || 14–16 |- style="background:#fbb" | 31 || May 24 || Dodgers || 0–5 || Billy Loes (5–0) || Russ Meyer (1–6) || None || 15,894 || 14–17 |- style="background:#bbb" | – || May 25 || Dodgers || colspan=6 | Postponed (rain); Makeup: September 2 |- style="background:#bbb" | – || May 26 || Braves || colspan=6 | Postponed (rain); Makeup: May 27 as a traditional double-header |- style="background:#fbb" | 32 || May 27 (1) || Braves || 2–4 (12) || Warren Spahn (4–3)