Stelios Demou Poyiadjis was born in Limassol, Cyprus in 1958. He studied medicine at the National and Capodistrian University in Athens and specialized in Paediatrics. In 1990 he began working in the Paediatric Oncology Unit of the Chris Hani Baragwanath Academic Hospital of the University of the Witwatersrand, in Johannesburg, South Africa, where he continues to work as at the date of this publication.
He compiled the Saint Siluan Early Warning Signs of Cancer in Children which has officially been adopted by the South African Department of Health, the International Society of Paediatric Oncology (Paediatric Oncology in Developing Countries) and the International Confederation of Childhood Cancer Parents Organizations.
The Saint Siluan Early Warning Signs in Children is being used internationally in developing and developed countries alike, and has been translated into several languages.
He is the author of The Kollyvas and Journey of A Doctor: In Search of the Spiritual Dimension of the Medical Profession.