2005 Washington Nationals season Game log May

| Date_ | Opponent | Score | Loss | Attendance | Record |
|---|---|---|---|---|---|
| May 1 | New York Mets | 3-6 | Ayala (1-1) | 27333 | 13-12 |
| May 2 | @ Los Angeles Dodgers | 6-2 | Erickson (1-3) | 34079 | 14-12 |
| May 3 | @ Los Angeles Dodgers | 2-4 | Rauch (0-1) | 41190 | 14-13 |
| May 4 | @ Los Angeles Dodgers | 5-2 | Pérez (4-2) | 33081 | 15-13 |
| May 6 | @ San Francisco Giants | 9-3 | Lowry (1-3) | 40425 | 16-13 |
| May 7 | @ San Francisco Giants | 11-8 | Accardo (0-1) | 40220 | 17-13 |
| May 8 | @ San Francisco Giants | 3-4 (13) | Rauch (1-2) | 36903 | 17-14 |
| May 9 | @ Arizona Diamondbacks | 4-3 | Valverde (0-1) | 19440 | 18-14 |
| May 10 | @ Arizona Diamondbacks | 2-3 | Armas (0-1) | 23181 | 18-15 |