As in all Human institutions whose aims are to assemble and to unite, the way towards unification was a very long and tedious one. The first association of Catholic Physicians was founded in France in 1884 during the Pontificate of Pope Leo XIII. This was an era of strong anti-Catholicism in France, Germany and England. Other countries saw the formation of Catholic Physicians Associations in the following years but their activities were confined to a local level.

The first attempt to coordinate these local guilds on an international level was the formation of an International Secretariat of National Societies of Catholic Physicians founded in Paris in 1924. This Secretariat kept up a regular correspondence with the existing groups and also helped in the formation of other groups. It also organized meetings of Catholic physician groups of European countries. This became the beginning of the International Congresses, the first of which was held in Brussels in 1935.

During the Fourth Congress, in Rome in 1949, a second secretariat was founded in Rome, which was independent of the one in Paris. In 1951, during the Fifth International Congress held in Paris, a new International Secretariat was temporarily formed combining the two previously existing secretariats. Its mission was to establish a genuine International Federation of Catholic Medical Associations. International Congresses were held in Dublin in 1954, in the Hague in 1956, in Brussels in 1958, in Munich in 1960 and in London in 1962.

At the time of the 11th. Congress held in Manila in 1966, the official Statutes and Bylaws of FIAMC were adopted by the General Assembly and approved by the Holy See. This was the legal and statutory birth of FIAMC. Since that time, other national associations from Australia, New Zealand, Africa and Latin America have become members of FIAMC, so that at present FIAMC has representation from all its six regions comprising the continents of the world. FIAMC then is truly a worldwide organization.

FIAMC has its permanent secretariat in the Vatican City (Diocese of Rome).