The 784th went into action late December 1944. Landing in France on Christmas Day 1944, the battalion consisted of six companies: A (Able), B (Baker), C (Charlie), D (Dog), Headquarters and Service Company. A, B and C Companies had M4 and M4A3 Medium Tanks while D company had M5A1 Stuart Light Tanks. Headquarters Company had a 105 mm assault platoon, a reconnaissance platoon and 81 mm mortar platoon.
On 31 December 1944, the 784th began official combat operations with the 104th Infantry Division. They participated in actions along the Roer River. On 3 February 1945, the 784th was released from duty with the 104th Division to the 35th Infantry Division. On 8 February 1945, the 784th joined the 35th Division in a major offensive. On 26 February 1945, Able Company of the 784th assisted elements of the 134th Infantry Regiment from the 35th Infantry Division in capturing the town of Hilfarth across the Roer River. The next day they captured the town of Wassenberg. Baker Company along with the 137th Regiment (35th Div) took Golkrath, a village at Erkelenz.