Organisationally, the MNS comprises a number of divisions and sections responsible for:

• Strategic Planning, Policy, Research and Evaluation - This Division is responsible for policy development, carrying out research to support the Ministry's activities and for developing and monitoring the Ministry's corporate plans;
• Security, Intelligence and Operations - This Division manages the Ministry's responsibilities for organised crime, counter-terrorism, narcotics, port security, security in tourist areas and protective security across government;
• Programme Management and Coordination - This Division is made up of a range of units: Parole Secretariat; Victim Support; Witness Protection; Inspectorate of Corrections and a range of administrative functions on behalf of the Ministry's departments;
• Modernisation and Special Projects - This Division manages on behalf of the Ministry, large information technology and other change programmes which affect the Ministry, its departments and agencies;
• Finance and Planning - This is the finance and accounting hub of the Ministry.  This Division also has responsibility for Corporate Planning.   It supports the Ministry and the Jamaica Defence Force.  The Department of Correctional Services, Jamaica Constabulary Force, Passport, Immigration and Citizenship Agency and Private Security Regulation Authority have developed responsibility for their finance and accounting;
• Internal Audit - The Internal Audit Unit is responsible for auditing the performance of both the Ministry and its departments and agencies;
• Human Resources and Administration - The Division is responsible for the Ministry's human resource needs and also manages a range of administrative functions such as office services, transport, property management and IS/IT;
• Legal Affairs - This is a single post holder who drafts legislation and advises the Ministry on all legal and risk management matters.

The Ministry is directly responsible for two departments: The Jamaica Constabulary Force and the Department of Correctional Services.  Both have their own mandates and delegated responsibility for management of all operational matters.

In addition, the Ministry acts as the ministerial "home" for the Jamaica Defence Force.  The JDF is directly accountable to the Prime Minsiter who is also the Minister of Defence.  There is currently no formal Ministry of Defence, and all defence matters are dealt with by a Defence Board.  The Minister of National Security, and the Permanent Secretary in the Ministry of National Security are members of the Defence Board, along with the Prime Minister and the Cabinet Secretary.

Currently, the MNS manages the JDF budget and undertakes some routine administrative functions on its behalf.  

At present, the Ministry is responsible for two statutory bodies:  The Private Security Regulations Authority, PSRA which handles the registration of private security companies and security guards; and The Firearm Licensing Authority, FLA, which monitors and regulates the issuance of firearm licences.

Also positioned under the portfolio of the MNS are The Passport, Immigration and Citizenship Agency, PICA, an Executive Agency, and the newly established Police Civilian Oversight Authority.  Plans are in place for the establishment of a Ports Security Agency, PSA.