Houston Astros
| Date | Transaction |
| 06/26/2012 | Scott Moore Purchased From Minors |
| 06/26/2012 | Travis Buck Designated for Assignment |
| 06/26/2012 | Travis Buck Recalled From Minors Rehab |
| 06/26/2012 | Fernando Martinez Sent to Minors |
| 06/23/2012 | Fernando Martinez Transferred to 15-Day DL; Concussion |
| 06/23/2012 | Bud Norris Sent to Minors for Rehabilitation |
| 06/21/2012 | Fernando Martinez Sent to Minors for Rehabilitation |
| 06/20/2012 | Hector Ambriz Signed to a Minor League Contract |
| 06/18/2012 | Travis Buck Sent to Minors for Rehabilitation |
| 06/17/2012 | Carlos Lee Recalled From Minors Rehab |
| 06/17/2012 | Sergio Escalona Transferred to 60-Day DL; Left elbow surgery - out for season |
| 06/17/2012 | Dallas Keuchel Purchased From Minors |
| 06/16/2012 | Brett Wallace Sent to Minors |
| 06/15/2012 | Fernando Abad Recalled From Minors Rehab |
| 06/14/2012 | Carlos Lee Sent to Minors for Rehabilitation |
| 06/09/2012 | Fernando Martinez Placed on 7-Day DL; Concussion |
| 06/09/2012 | Matt Downs Called Up from Minors |
| 06/08/2012 | Brian Bixler Called Up from Minors |
| 06/08/2012 | Fernando Abad Sent to Minors for Rehabilitation |
| 06/03/2012 | Brett Wallace Called Up from Minors |
| 06/03/2012 | Jordan Lyles Called Up from Minors |
| 06/02/2012 | Fernando Martinez Called Up from Minors |
| 06/02/2012 | Matt Downs Sent to Minors |
| 05/28/2012 | Enerio Del Rosario Sent to Minors |
| 05/28/2012 | Jordan Lyles Called Up from Minors; recalled as 26th roster player |
| 05/28/2012 | Jordan Lyles Sent to Minors |
| 05/28/2012 | David Carpenter Called Up from Minors |
| 05/27/2012 | Brian Bass Signed to a Minor League Contract |
| 05/27/2012 | Xavier Cedeno Purchased From Minors |
| 05/26/2012 | Justin Ruggiano Traded to Miami Marlins; for C Jobduan Morales |
| 05/21/2012 | Armando Galarraga Signed to a Minor League Contract |
| 05/21/2012 | Enerio Del Rosario Called Up from Minors |
| 05/20/2012 | Jordan Lyles Sent to Minors |
| 05/15/2012 | Jordan Lyles Called Up from Minors |
| 05/15/2012 | David Carpenter Sent to Minors |
| 05/09/2012 | Rhiner Cruz Recalled From Minors Rehab |
| 05/08/2012 | Enerio Del Rosario Sent to Minors |
| 05/08/2012 | Aneury Rodriguez Called Up from Minors |
| 05/08/2012 | Aneury Rodriguez Sent to Minors |
| 05/05/2012 | Rhiner Cruz Sent to Minors for Rehabilitation |
| 05/02/2012 | Enerio Del Rosario Called Up from Minors |
| 04/30/2012 | Marwin Gonzalez Reinstated from Paternity Leave List |
| 04/29/2012 | Brian Bixler Sent to Minors |
| 04/29/2012 | Jordan Lyles Called Up from Minors |
| 04/29/2012 | Jordan Lyles Sent to Minors |
| 04/27/2012 | Brian Bixler Called Up from Minors |
| 04/27/2012 | Fernando Abad Called Up from Minors |
| 04/27/2012 | Marwin Gonzalez Placed on Paternity Leave List |
| 04/11/2012 | Jed Lowrie Recalled From Minors Rehab |
| 04/11/2012 | Brian Bixler Sent to Minors |
| 04/10/2012 | Jed Lowrie Sent to Minors for Rehabilitation |
| 04/09/2012 | Fernando Abad Sent to Minors |
| 04/08/2012 | Justin Maxwell Acquired Off Waivers from New York Yankees |
| 04/06/2012 | Brian Bixler Purchased From Minors |
| 04/04/2012 | Travis Buck Purchased From Minors |
| 04/04/2012 | Henry Sosa Outrighted to Minors |
| 04/03/2012 | J.B. Shuck Sent to Minors |
| 04/02/2012 | Jordan Lyles Sent to Minors |
| 04/01/2012 | Alberto Arias Released |
| 04/01/2012 | Brett Wallace Sent to Minors |
| 03/30/2012 | Livan Hernandez Released |
| 03/30/2012 | Lance Pendleton Released |
| 03/29/2012 | Jack Cust Cleared Waivers and Became a Free Agent |
| 03/28/2012 | Enerio Del Rosario Sent to Minors |
| 03/27/2012 | Jack Cust Released |
| 03/27/2012 | Zach Duke Released |
| 03/23/2012 | Fernando Martinez Sent to Minors |
| 03/23/2012 | Aneury Rodriguez Sent to Minors |
| 03/23/2012 | Jimmy Paredes Sent to Minors |
| 03/20/2012 | Humberto Quintero Traded to Kansas City Royals; for LHP Kevin Chapman, four-player deal |
| 03/20/2012 | Jason Bourgeois Traded to Kansas City Royals; for LHP Kevin Chapman, four-player deal |
| 03/15/2012 | Juan Abreu Sent to Minors |
| 03/14/2012 | Landon Powell Signed to a Minor League Contract |
| 02/24/2012 | Fernando Martinez Signed; avoids arbitration |
| 02/24/2012 | Sergio Escalona Signed; avoids arbitration |
| 02/24/2012 | Wilton Lopez Signed; avoids arbitration |
| 02/08/2012 | Jed Lowrie Signed; avoids arbitration |
| 02/06/2012 | Justin Ruggiano Signed to a Minor League Contract |
| 02/02/2012 | Mike Hessman Signed to a Minor League Contract |
| 02/01/2012 | Angel Sanchez Outrighted to Minors |
| 01/31/2012 | Livan Hernandez Signed to a Minor League Contract |
| 01/29/2012 | Jordan Brown Signed to a Minor League Contract |
| 01/27/2012 | Zach Duke Signed to a Minor League Contract |
| 01/24/2012 | Chris Snyder Signed as Free Agent; one-year contract |
| 01/24/2012 | Angel Sanchez Designated for Assignment |
| 01/23/2012 | Craig Tatum Acquired Off Waivers to Arizona Diamondbacks |
| 01/20/2012 | Henry Villar Outrighted to Minors |
| 01/18/2012 | Jack Cust Signed as Free Agent; one-year contract |
| 01/18/2012 | Craig Tatum Designated for Assignment |
| 01/17/2012 | J.A. Happ Signed; avoids arbitration |
| 01/11/2012 | Fernando Martinez Acquired Off Waivers from New York Mets |
| 01/11/2012 | Henry Villar Designated for Assignment |
| 12/16/2011 | Brian Bixler Outrighted to Minors |
| 12/14/2011 | Jed Lowrie Traded from Boston Red Sox; with P Kyle Weiland for P Mark Melancon |
| 12/14/2011 | Brian Bixler Designated for Assignment |
| 12/14/2011 | Nick Stavinoha Signed to Play in Japan; Hiroshima Carp |
| 12/14/2011 | Mark Melancon Traded to Boston Red Sox; for 2B Jed Lowrie & RHP Kyle Weiland |
| 12/14/2011 | Kyle Weiland Traded from Boston Red Sox; with 2B Jed Lowrie for RHP Mark Melancon |
| 12/12/2011 | Humberto Quintero Signed; avoids arbitration |
| 12/08/2011 | Marwin Gonzalez Traded from Boston Red Sox; for RHP Marco Duarte |
| 12/08/2011 | Rhiner Cruz Drafted Via Rule 5 |
| 12/02/2011 | Diory Hernandez Signed to a Minor League Contract |
| 11/29/2011 | Carlos Corporan Signed to a Minor League Contract |
| 11/18/2011 | Carlos Corporan Refused Minor League Assignment - Free Agent |
| 11/18/2011 | Lance Pendleton Signed to a Minor League Contract |
| 11/16/2011 | Carlos Corporan Outrighted to Minors |
| 11/15/2011 | Scott Moore Signed to a Minor League Contract |
| 11/13/2011 | Joe Thurston Signed to a Minor League Contract |
| 11/12/2011 | Brad Snyder Signed to a Minor League Contract |
| 11/09/2011 | Travis Buck Signed to a Minor League Contract |
| 11/09/2011 | Nick Stavinoha Signed to a Minor League Contract |
| 11/03/2011 | Brian Bixler Acquired Off Waivers from Washington Nationals |