It is one of the smallest military forces in the world, with its different branches having varied functions including: performing ceremonial duties; patrolling borders; mounting guard at government buildings; and assisting police in major criminal cases.

National defence in the face of an aggressive world power is, by arrangement, the responsibility of Italy's armed forces.

[5] Although once at the heart of San Marino's army, the Crossbow Corps is now an entirely ceremonial force of about 70 volunteer soldiers.

[6] By the mid-twentieth century, the Crossbow Corps had become largely defunct, save for parading on state holidays; but in 1956 the practice of training its members in crossbow shooting was revived, and a 'Crossbow Federation' was formed to encourage competition in this art, so that the unit (although still entirely ceremonial in nature) now again has a very active existence.

[7] The Guard of the Rock (Italian: Guardia di Rocca) is a front-line military unit in the San Marino armed forces.

[10] This unit, formed in 1740, is composed almost entirely of volunteers, and its duties are largely ceremonial, although members undergo full military training.

[11] Due to its striking uniform, it is arguably the best-known part of the Sammarinese military, and appears on countless postcard views of the republic.

In former times all families with two or more adult male members were required to enroll half of them in the Company of Uniformed Militia.

[12] It is a matter of civic pride for many Sammarinese to belong to the force, and all citizens with at least six years residence in the republic are entitled to enroll.

Both male and female soldiers belong to the Company of Uniformed Militia, although men predominate in numbers.

The Gendarmerie may call upon the assistance of the Municipal Police in cases of major crime or national security, and (following revised regulations for both corps introduced by the Government of San Marino in 2008) may also call upon soldiers and border guards of the Fortress Guards Corps, in their secondary role as 'Criminal Police Officers'.

The Municipal Police (Corpo di Polizia Civile) is not part of the armed forces of San Marino, but it does work closely with them, particularly with the Gendarmerie.