The officer Sen Con Scott Mason, from Cue in Western Australia, first rescued Cuejo the joey in March after his mother was hit and killed by a truck.
Cuejo had a second brush with death on 27 April when a wedge-tailed eagle grabbed him in the Burringurrah police station yard.
Sen Con Mason said the eagle lifted Cuejo over a 2m-high fence.
He told the Australian Broadcasting Corp. that he chased after the eagle, which landed a short distance away.
A second eagle joined the attack, but Sen Con Mason frightened the birds while Cuejo bolted away.
"I finally caught up with him a few hundred metres down the way and found out that he was bleeding quite heavily," he said.
Cuejo suffered wounds to his chest and face, and lost hair from his back.
The little kangaroo is the star of the Cue Police Twitter account and sometimes hops around after Sen Con Mason on duties.
An Australian police officer has fought off eagles to save the life of his adopted baby kangaroo.