Nguyen Duc Minh, 35, entered a local branch of Agribank on January 26 wearing a mask and armed with a gun and what appeared to be a grenade.
He made his escape by motorbike with a bag stacked with cash.
Police tracked down Minh the following day.
|CCTV footage shows a man wearing face mask and a black cap robbing the Agribank in Bac Giang Province on January 26.
Details of the swift arrest have not been released, but investigators said they have recovered 90% of the money and discovered the grenade was a fake.
Bank robberies are becoming more frequent in Vietnam, with most cases involving just a single individual.
Multiple attempts were reported last year.
In October, a man in the northern province of Bac Ninh was arrested after holding bank workers at knifepoint and stealing VND200 million (US$8,800).
In September, two heists cleared a combined US$10,000 in the southern provinces of Dong Nai and Vinh Long. No arrests have been reported.
In the same month, a court in the southern province of Tra Vinh sentenced a man to 20 years in jail for using an air gun to rob US$88,000 from a bank in May.