Prof. Chrousos directs the oldest, largest and most prestigious Department of Pediatrics in Greece and has had major impact on the way Pediatrics and Medicine are practiced. For instance, he developed new national growth curves, initiated a national campaign against childhood obesity, chaired the National Council on Breast Feeding, developed an administrative mechanism for certifying baby-friendly hospitals, started a national campaign for breast feeding (UNICEF Award 2011), initiated a longitudinal study of children conceived by assisted reproductive technologies and discovered significant epigenetic effects of these procedures in childhood cardiometabolic health (Academy of Athens Award 2011), established two graduate programs in “Pediatric and Nursing Research”, and in the “Science of Stress and Health Promotion”, established the first Adolescent Medicine Program in the country and helped with the founding of a new biomedical research institute (Biomedical Research Foundation of the Academy of Athens).

In 2010, the prototypic Adolescent Medicine Program that he established at the University of Athens was recognized as the unique UNESCO Chair in Adolescent Health Care. He served as vice-President of the Greek National Council of Research and Technology. Prof. Chrousos was a founding Member and member of the Board of the Association for Patient-Oriented Research,  the World Innovation Foundation, the Council of the European Society for Clinical Investigation and a member of MEDINE, the Medical Education in Europe. He serves as  President of the Hellenic Society of Pediatric and Adolescent Endocrinology since 2006, president  Hellenic College of Pediatrics since 2006,  president of the European Society for Clinical Investigation and president of the  European Academy of Pediatrics since 2009. He is a member of the Council of European Society of Pediatric Endocrinology , a fellow at the Mind and Life Institute in New York. He is Chairman, of the Scientific Council, ELEPAP,  of the Greek Society for the Protection of Handicapped Children and he is also Chairman of the Scientific Council, Health for All and  president of the Institute of Stress Biology and Medicine and president of the Hellenic Society of Developmental and Behavioral Pediatrics and Adolescent Medcine. Furthermore, Prof. Chrousos founded the Hellenic College of Pediatrics, the Hellenic Society of Developmental Pediatrics and Adolescent Medicint, the Institute of Stress Biology and Medicine and the NGO “Health for All” for the support of vulnerable populations in Greece.

Prof. Chrousos’s professional  memberships include the American Society for Clinical Investigation, the Association of American Physicians, the Society for Pediatric Research, the American Pediatric Society, the Endocrine Society Lawson Wilkins Society for Pediatric Endocrinology, the Society for Neuroscience American Federation for Clinical Research, the American Academy of Pediatrics, the American College of Physicians , the New York Academy of Sciences, the American Diabetes Association, the International Brain Research Organization, the International Society for Psychoneuroendocrinology Molecular Medicine Society , the European Society for Clinical Investigation , the American College of Endocrinology , the European Society for Pediatric Endocrinology and the  Association of Program Directors in Endocrinology and Metabolism.