Nationals Roster & Staff
Transactions
| Date | Transaction |
| 08/28/12 | Washington Nationals signed free agent SS Edwin Lora to a minor league contract. |
| 08/22/12 | Washington Nationals signed free agent RHP Luis Reyes to a minor league contract. |
| 08/20/12 | SS Cesar Izturis elected free agency. |
| 08/17/12 | Washington Nationals activated SS Ian Desmond from the 15-day disabled list. |
| 08/17/12 | Washington Nationals designated SS Cesar Izturis for assignment. |
| 08/12/12 | Washington Nationals sent Atahualpa Severino outright to Syracuse Chiefs. |
| 08/08/12 | Washington Nationals signed free agent RHP Reynaldo Lopez to a minor league contract. |
| 08/06/12 | Washington Nationals claimed SS Cesar Izturis off waivers from Milwaukee Brewers. |
| 08/06/12 | Washington Nationals designated Atahualpa Severino for assignment. |
| 08/06/12 | Washington Nationals placed LF Mark DeRosa on the 15-day disabled list retroactive to August 5, 2012. Left abdominal strain. |
| 08/06/12 | Washington Nationals signed free agent RHP Ramses Rosario to a minor league contract. |
| 08/06/12 | Washington Nationals signed free agent OF Aldrem Corredor to a minor league contract. |
| 08/06/12 | Washington Nationals signed free agent OF Darryl Florentino to a minor league contract. |
| 08/06/12 | Washington Nationals signed free agent OF Luis Guzman to a minor league contract. |
| 08/06/12 | Washington Nationals sent Carlos Maldonado outright to Syracuse Chiefs. |
| 08/04/12 | Washington Nationals optioned John Lannan to Syracuse Chiefs. |
| 08/04/12 | Washington Nationals designated Carlos Maldonado for assignment. |
| 08/04/12 | Washington Nationals optioned Sandy Leon to Syracuse Chiefs. |
| 08/03/12 | Washington Nationals designated Carlos Maldonado for assignment. |
| 08/03/12 | Oakland Athletics traded cash and C Kurt Suzuki to Washington Nationals for C David Freitas. |
| 08/03/12 | Oakland Athletics traded cash and C Kurt Suzuki to Washington Nationals for C David Freitas. |
| 08/03/12 | Washington Nationals designated Carlos Maldonado for assignment. |
| 08/03/12 | Washington Nationals recalled John Lannan from Syracuse Chiefs. |
| 08/03/12 | Oakland Athletics traded cash and C Kurt Suzuki to Washington Nationals for C David Freitas. |
| 08/02/12 | Washington Nationals activated RF Jayson Werth from the 60-day disabled list. |
| 08/02/12 | Washington Nationals placed RHP Henry Alberto Rodriguez on the 15-day disabled list retroactive to August 1, 2012. Low back strain. |