Police in the central city arrested Nguyen Huu Thanh, 32, for "fraudulent appropriation of assets" on Thursday.
They seized from him a fake police identity card and government agencies' seals he had used to scam people who wanted to go abroad to work or study in the U.S., Canada and Australia.
Thanh looked up procedures for people to go, live and study abroad online, and spread the word that he could help complete such procedures quickly.
He opened a fake law office in Son Tra District as a cover for his illegal activities.
An investigation found that in the last year he had tricked 17 people, including seven from Ho Chi Minh City, and took VND10 billion (US$407,000) from them.
He told the police he had spent all the money.
One of the victims complained about a suspected con to the police, who then began the investigation.