The official establishment took place on 6 April 1862 by a Decree of the Supreme Council; the same act introduced the crown on top of the shield.

2 from the winter of 1963–64 is reproducing on page 31 an "official plate showing the flag and arms of San Marino, [which] was a gift of the Sammarinese government, through its Consul in New York City."

[2] In 2011, a new Law on the flag and coat of arms of San Marino presented a slightly simplified design, the main changes being that the branches have no more ramifications, the towers are square instead of round, and the gates are oriented now towards sinister.

The oldest surviving examples of the coat of arms of San Marino come from seals dated to 14th and 15th centuries and conserved in the State Archive.

[3] The official description of the coat of arms is: "The official coat of arms of the Republic is surmounted by a closed crown, the symbol of sovereignty The shield is azure, three mountains vert, towers argent, windowed, embattled and masoned sable, surmounted by ostrich plumes argent.