The operation was carried out during a 45-day campaign to review and clean up residential areas across the city.
Authorities said 22 inspection teams checked 420 accommodation facilities and found 84 cases where operators had failed to report the presence of foreign guests as required by law.
Investigators also identified nearly 300 foreign nationals showing signs of illegal entry, unlawful employment, gambling activities and online fraud.
In a notable case on June 8, police discovered a group of 83 Chinese nationals who had rented an entire hotel in Binh Duong Ward. Most were believed to have entered Vietnam illegally from Cambodia.
During the inspection, officers seized computers, mobile phones and other electronic devices suspected of being used for online activities.
Preliminary investigations suggest the group may have been involved in fraud targeting Chinese citizens, police said.
The case remains under investigation as police work to determine the full scope of the suspected operation.
Police said the discovery helped prevent the formation of transnational high-tech crime networks in the city.
Investigators are also examining whether some accommodation providers assisted foreign nationals residing illegally in Vietnam by failing to comply with residency reporting requirements.