While in Vietnam the 9th Engineer Battalion was responsible for the repair and mine sweeps of many of the major highways and bridges, for camp construction, for building ferries and for supporting the army and many foreign units on the battlefront.

Company A, 9th ESB was the lead element in planning and conducting humanitarian construction operations in East Timor from September to December 2000.

[1] In September 2008, 9th ESB deployed for a second tour in support of Operation Iraqi Freedom (seven months long); they returned in March 2009.

During the deployment, the battalion repaired roads, built working spaces and performed force protection construction and upgrades.

9th ESB's most recent deployment (and second tour) was to Helmand Province in Afghanistan in support of Operation Enduring Freedom (OEF) which occurred from November 2011 to June 2012.