The Hellenic Society of Medical Oncology (HeSMO) is a non-profit scientific group founded in 1986 in Athens by 22 founding members. The aim of HeSMO is to enhance tuition and updates in the area of clinical oncology as well as to promote prevention, diagnosis, treatment and research on malignant neoplasms.

The first charter of HeSMO was voted and validated during the first meeting of the founding members in Athens at the hotel "St George Lycabetus" on the 4th of July 1985. In 1997, HeSMO acquired its own Headquarters located at 105 Alexandras Avenue (4th floor) where a library and a members-only meeting room are also situated. Since March 1999 the Society has got its own website.

HeSMO organised its first Hellenic Congress of Clinical Oncology in 1992 and since then the Society constantly organises a similar Congress every 2 years.