Attended the University of Athens Medical School, Greece. First-year postgraduate training was received in Internal Medicine at Grant Hospital, Chicago, Illinois (1976-1977); Residency Program completion in Internal Medicine at Cook County Hospital, Chicago, Illinois (July, 1977 – June, 1979). He completed a fellowship in the Division of Gastroenterology at Cook County Hospital, Chicago, Illinois (July, 1979-June, 1981). He was a Research Associate, Hektoen Institute for Medical Research, Cook County Hospital, Chicago, Illinois with major in Peptic Ulcer Disease (PUD) and Prostaglandins; Dr. Giannikopoulos was the Chief of Gastroenterology at Charles Drew University of Medicine and Science, King-Drew Medical Center, Department of Medicine. He has been affiliated with King-Drew Medical Center since December, 1983.