The Brigade is structured on three commando units, which are reinforced by the combat support and combat service support units from within the force. These provide the necessary specialist skills to meet the complex and very specialised tasks required by an amphibious assault force engaged in rapid reaction intervention, and to sustain it in those tasks. In transition to war Royal Marines Reservists as well as Territorial Army Commando gunners, engineers and logisticians enhance the Brigade. Otherwise it is in all respects a self-contained force, well capable of fully deploying its leading elements and logistic support within five days, as demonstrated during Operation Haven, when the Brigade deployed to northern Iraq following the first Gulf war at very short notice.

United Kingdom Landing Force Command Support Group (CSG) facilitates the Command, Control and Communications and computing (C4) function for the Brigade Headquarters as well as being responsible for the Intelligence, Surveillance, Target Acquisition and Reconnaissance (ISTAR) feed in the HQ. In essence, it ensures Information Dominance for the Brigade. Most of these specialist assets would only be found at divisional level within the Army.

Brigade Patrol Troop consists of four six-man teams. They work ahead of the main force in a reconnaissance role, collecting information on the enemy and reporting back directly to the Brigade HQ. They are often deployed in advance of the main amphibious landings.

Y Troop are the electronic warfare specialists. equipped with cutting-edge communications intercept equipment, they can locate and exploit enemy transmissions, providing high-level, real-time intelligence.

Communications Squadron is manned by Royal Marines signallers and provides secure communications for the Brigade HQ to its units. In addition, it provides satellite communications from any location in the world to a rear-link command or seaborne headquarters, and to the Permanent Joint Headquarters in Northwood.

Air Defence Troop is equipped with the new High Velocity Missile (HVM) and detachments are employed on point defence tasks for high-value targets such as Brigade HQ or supply dumps.

Royal Marines Police Troop co-ordinates vehicle movements out of the beachhead, marks the main supply routes and provides convoy escorts. In addition, they provide close protection for the Brigade Commander.

Medium Reconnaissance While there is no longer a designated unit linked to the Brigade, if required for a particular operation, an Army squadron of light armoured vehicles would be attached. This happened in Iraq in 2003, when a squadron from the Queens Dragoon Guards joined the Brigade.

The Commando Units 40, 42 and 45 Commandos are the core manoeuvre units of the Brigade and provide its immediate combat capability. Each is 700-men strong and can deploy as a Commando Group including in its orbat elements from the combat support units.

29 Commando Regiment Royal Artillery provides and co-ordinates fires for the Brigade. This can come from its own eighteen 105mm Light Guns, from other national or allied artillery units from aviation or Close Air Support or from the ships of the Fleet; for which the Regiment provides Tactical Air Control Parties and Naval Gunfire Observation Officers.

59 Independent Commando Squadron Royal Engineers provides close engineer support to the Brigade, with tasks ranging from bridge demolition to bridge building and from mine clearance to minelaying. General engineer support in the Brigade rear area is provided by 131 (V) Independent Commando Squadron Royal Engineers.

Commando Logistic Regiment Royal Marines consists of a Headquarters Squadron and four specialist squadrons providing logistic support, medical and workshop facilities for the Brigade. The Regiment is responsible for all second-line combat service support and is unique in the UK in providing all four Combat Service Support functions in a single regiment.

539 Assault Squadron Royal Marines operates landing craft, raiding craft and hovercraft, providing additional mobility to the assault force. The Squadron can also be used to support pre-landing operations. For amphibious landings the Squadron may be supplemented by additional craft from 4, 6 and 9 Assault Squadrons Royal Marines based on the amphibious ships.

HQ Commando Helicopter Force commands the aviation support to the Brigade. This consists of two squadrons of support helicopters, equipped with Sea King, and a squadron of light helicopters, equipped with Lynx and Gazelle.

Elements of Special Forces could be attached, primarily for advance force operations, as was the case in the Falklands conflict. Traditionally these come from the Special Boat Service; however, on Op TELIC the US Navy SEALs operated with the Brigade on the Al Faw peninsula.