The detainees -- all Vietnamese from southern Dong Nai Province and some northern provinces -- were nabbed mid-February, police in Dong Nai said in an online statement.
The gang, which had a woman ringleader, had "transferred money amounting VND2 trillion (US$78.5 million) for gambling and online fraud for a cross-border organization headquartered in Cambodia" since July 2024, police said.
They had set up 30 companies and made 150 business bank accounts to transfer and legalize money that had been obtained through fraud or gambling, the police said.
In January, Vietnam police arrested five people and smashed a similar cross-border money laundering ring worth $1.2 billion.
In October, Vietnamese property tycoon Truong My Lan was jailed for life on money laundering charges, although she is appealing the verdict.
The property developer had already been handed the death penalty for fraud totaling $27 billion in a separate case.