In the video, which was filmed in Podgorica, the capital of Montenegro, a man in a yellowhoodie is seen following a woman down a residential street, the Daily Mail reports.
Meanwhile, a black dog, believed to be a stray, watches intently.
The man grabs the woman from behind, causing her to fall to the ground, before trying to grab her handbag.
But the dog springs into action, biting the man's buttocks and legs.
The would-be robber then abandons the theft and runs away as the dog chases after him.
The video, which was posted on the Facebook group Podgoricki vremeplov, a group for people living in Podgorica, has since gone viral, with over 4,000 likes on Facebook.
