IUMS is one of the 31 Scientific Unions of the International Council of Science (ICSU). It was founded in 1927 as the International Society of Microbiology, and became the International Association of Microbiological Societies affiliated to the International Union of Biological Sciences (IUBS) as a Division in 1967. It acquired independence in 1980 and became a Union Member of ICSU in 1982.

The objectives of the Union are

• to promote the study of microbiological sciences internationally:
• initiate, facilitate and coordinate research and other scientific activities which involve international cooperation;
• ensure the discussion and dissemination of the results of international conferences, symposia and meetings and assist in the publication of their reports;
• represent microbiological sciences in ICSU and maintain contact with other international organizations. 

The major goal of IUMS is to promote research and the open exchange of scientific information for advancement of the health and welfare of humankind and the environment and strongly discourages any uses of knowledge and resources to the contrary >> read more

The scientific activities of the Union are conducted by the three Divisions of Bacteriology & Applied Microbiology (BAM), Mycology and Virology and by six specialist international committees, eight international commissions and two international federations. Their major activities include the classification and nomenclature of bacteria, fungi and viruses, food microbiology, medical microbiology and diagnostics, culture collections, education, and biological standardization.