On Cato Neimoidia, Delta Squad killed Plo Koon.
On the second level, they arrived on Mygeeto to eliminate Ki-Adi-Mundi. He could only be wounded when he threw his lightsaber.
On Utapau they had to confront Obi-Wan Kenobi, but he escaped. Obi-Wan Kenobi used the Force to throw rocks at them.
On the fourth level, the Deltas had to land on Kashyyyk, and this time they had to kill two Jedi, Luminara Unduli and Yoda. In the end, Yoda escaped.
Anakin Skywalker and the Deltas had to kill Cin Drallig and many others from the Jedi Temple during Operation: Knightfall.
When Order 66 is on hand, Delta Squad refuses to kill all of the Jedi, but the Chancellor vetoes their choice, so they have to.