He studied medicine at the University of Athens and trained in Munich in neuropsychiatry. He continued his studies in France and Italy. He returned to Athens (1871) and worked as a physician. In 1879 he was appointed associate professor of forensic medicine and toxicology. In 1881 he became a full professor. He was the founder of the toxicology laboratory.

In 1884-85 he became dean of the Medical School. He published the scientific – medical journal“Galenos” together with the lecturer George Makka and two other scientists Delaporta and Skiadaresis. He wrote studies and published mainly psychiatric writings : Elements of Forensic Medicine, Methods of Poison Detection, Study on Love Stroke etc.

Ach. Georgantas was a member of the Grand Lodge of Greece.