By the end of World War II, the influx of migrants from China to Hong Kong to flee Communist rule resulted in immigration control.

The boat was burnt with evidence destroyed, and the Hong Kong government-issued documents were hidden to cover up, later the ROC Ministry of National Defense repeatedly denied on the journalists' reportages and the parliament questioning, until being exposed by the publication of General Hau Pei-tsun's diary in 2000, known as the Lieyu Massacre.

[5][6][7] Prior to the handover of Hong Kong in 1997, the Immigration Department was responsible for processing BN(O) passport applications, which is now handled by the government of the United Kingdom.

As with all of the HK Disciplined Services, British-pattern ranks and insignia continue to be utilised, the only change being the exchange of the St. Edward's Crown for the Bauhinia Flower crest post-1997.

The ranks and insignia are listed below with their UK equivalences: In February 2024, the Immigration Department announced that all visa applicants would be subject to a national security risk test.

[17] In April 2024, a person from Reporters Without Borders (RSF) was searched multiple times at the airport before being denied entry into Hong Kong.

[24] In December 2022, freelance photographer Michiko Kiseki was not allowed into the city, after hosting an exhibition of photos from the 2019-20 Hong Kong protests.

The department is also tasked with preventing visits by prominent foreign human rights and democracy advocates, upon the direction of either the city or the mainland government.