On the 1st of July 1831 in Walachia, and, respectively, on the 1st of January 1832, in Moldavia, when the Organic Regulations came into force, the naming of Ministry of Domestic Affairs was used for the first time. It will be known as the Ministry of Interior later on, dealing with the management of the general administration of the country, public order and state safety, as well as the coordination of certain important sectors of social and economical activity.

On the 1st of November 1892 - when “The Law regarding the organizing of the exterior administrative authorities, which are dependent of the Ministry of Interior, and the establishing of the administrative circumscriptions” was approved, the territorial units pf the Ministry of Interior were also organized. Therefore, the Ministry of Interior consisted of: general administrative inspectorates, county prefect’s offices, county sub-prefect’s offices and small rural district (called “plasi”) sub – prefect’s offices, mayors of urban and rural villages.

On the 20th of June 1913 - a new law was adopted, regarding the structure of the Ministry of Interior. Therefore, the ministry consisted of central and special services. Among other special services, there were the General Directorate of Sanitary Service, the General Directorate of Telegraphs, Mail and Telephones, the General Directorate of Prisons, the Official Monitor, and the State Publishing House.

On the 22nd of June 1919 - , by means of a Decree – Law, the structure of the Ministry of Interior covered the whole Great Romania.

The Deputies’ Assembly adopted “the Administrative Law” on the 21st of July 1929, and the Senate adopted it on the 25th of July. The Prefect, being the head of the county administration, was the representative of the government in the county and was appointed on the basis of a Royal Decree.

“The Ministries Law” was adopted on the 2nd of August 1929 which also included the Ministry of Interior. Among other attributions given to this ministry, we mention the following ones: leading the country’s general administration, the state order and safety, local administration control etc.

"The Organizational Regulation of the Ministry of Interior” from the 25th of January 1930 brought back the definition of the Ministry of Interior given by the Organic Regulation almost a century earlier, stipulating that “It is the Ministry’s of Interior attribution to assure the general administration of the country and the state order and safety”.

"The Law regarding the organizing of the Ministry of Interior” from the 4th of January 1936 stipulated that the institution, as a political factor in charge with the domestic order of the state, had a double mission: assuring the general administration of the country and defending public order and state safety. Besides the Ministry of Interior, there were functioning, as attached institutions, the National Office of Tourism, the National Office of Population Defense Against Air Attacks, the Office of Radio Broadcasting and Cinema, and the General Institute of Statistics;

The Ministry of Public Order was created on the 28th of September 1939 whose attributions were the management of the State General Police and the Gendarmerie. This ministry was dissolved on the 3rd of October, the same year, its competencies being taken over by the Ministry of Interior.

In 1941, the Ministry of Interior changed its naming into the Ministry of Domestic Affairs.

In 1947, a new restructuring of the Ministry of Domestic Affairs took place and several services of the central and local administration were included in it. The Border Police, known as “Graniceri”, which were created in 1904, were taken over by the Ministry of Interior and remained there till 1960 when they were transferred to the Ministry of National Defense. After the events from 1989, they went back to the Ministry of Interior. ;

On the 30th of August 1948, the Decree no. 221 stipulated that the General Directorate of the People’s Security became part of the Ministry of Domestic Affairs.

16 martie 1949 – Ministerul Afacerilor Interne a primit o noua organizare prin Decretul nr.102, institutia urmând a fi condusa de un ministru, ajutat de un consiliu, ministrii adjuncti si consilieri ministeriali.

On the 20th of September 1952, the Decree no. 324 reorganized the Ministry of Domestic Affairs. Therefore, the Ministry of State Security was born which was a central distinct structure.