Vu Thi Ngoc Bich, 42, was accused of engaging in sex work and fined BND500 ($364).
When she was arrested in a hotel in the Jalan Gadong area in Bandar Seri Begawan, Brunei’s capital, her money and cell phone were confiscated.
The Borneo Bulletin reported that the Bandar Magistrate’s Court on November 21 sentenced her to a month in jail for failure to pay the fine.
Bich was arrested on November 12, 2018 in a raid by the Brunei's criminal investigation police.
In September, Brunei police had detained two Vietnamese women for suspected prostitution in the capital city’s Tutong District.
In August, nine Vietnamese were detained in an anti-prostitution raid in Melaka state in Malaysia.