[1] The flag consists of a yellow field and three horizontal red stripes, and can be explained as emblematic of the common blood running through northern, central, and southern Vietnam.

After the deportation and exile of the emperors Thành Thái and Duy Tân by the French colonialists, the new pro-French emperor Khải Định introduced new imperial flag as a yellow flag with single horizontal band of red, following the Imperial Order of the Dragon of Annam.

In 1945 with the French ousted by Japan, Prime Minister Trần Trọng Kim of the newly restored Empire of Vietnam adopted another variant of the yellow flag.

On 2 June 1948, the prime minister of the Provisional Central Government of Vietnam, Brigadier General Nguyễn Văn Xuân, signed the decree with the specifications for the Vietnamese national flag as follows: "The national emblem is a flag of yellow background, the height of which is equal to two-thirds of its width.

"[8] The new national flag was raised for the first time on 5 June 1948 on a boat named Dumont d'Urville outside of Hạ Long Bay during the signing of the Halong Bay Agreements (Accords de la baie d’Along) by High Commissioner Emile Bollaert and Nguyễn Văn Xuân.

The residents of Hanoi were requested to display the flag at their home on 5 June 1948 to celebrate the Hạ Long Bay event.

With the capitulation of Saigon on 30 April 1975, the Republic of Vietnam came to an end and the flag ceased to exist as a state symbol.

In modern Vietnam, even though it is not directly mentioned, the display and usage of the South Vietnamese flag is criminalized under the representation of "Making, storing, spreading information, materials, items for the purpose of opposing the State of Socialist Republic of Vietnam" (tội làm, tàng trữ, phát tán hoặc tuyên truyền thông tin, tài liệu, vật phẩm nhằm chống Nhà nước Cộng hòa xã hội chủ nghĩa Việt Nam) alongside other potential convictions related to the violations of national security and anti-State as defined by the country's Criminal Code, practically prohibiting the display of the so-called yellow flag beyond reasonable educational purposes and occasions.