He was born in Athens in 1971 and graduated from the School of Medicine of the University of Patras (1996). He completed his Urology residency at the Urology Clinic of Larissa University Hospital (2004) and received his PhD from the University of Thessaly in 2010. He received further education at the Extracorporeal Lithotripsy Unit of the 2nd University Urology Clinic of Athens (2005) and in Paediatric Urology at the Paediatric Urology Clinic of the University of Innsbruck in Austria (2007). He became involved in Clinical Urology, after completing his residency at the University Urology Clinic of the University General Hospital of Larissa, initially as an unpaid scientific associate (2004-2006) and subsequently as an Assistant Registrar and Junior Registrar (2006 to date). In October 2010, he was proclaimed Urology Lecturer at the University of Thessaly. His clinical activities focus on Endourology - Urinary System Calculus, Neuro-Urology – Urodynamics, Uro-oncology and Paediatric Urology. In 2005, he organised, developed and operated the Extracorporeal Lithotripsy Unit of the University Urology Clinic of the University General Hospital of Larissa from its very early days. It should be noted that this Unit is the only such Unit in Greece with a Quality Management System certified according to ISO 90001:2008, with Mr Karatzas as Head of Quality of the Unit. He also headed the Neuro-urology – Urodynamics Unit of the University Urology Clinic of the University General Hospital of Larissa from 4/2007 to 10/2007, 4/2008 to 8/2008 and from August 2009 to August 2010. Finally, in cooperation with the University Pediatrics Clinic of the University General Hospital of Larissa, he organised and ran the Paediatric Urology Clinic and the Child Incontinence and Enuresis Clinic (within the context of the Neuro-urology – Urodynamics Unit operation) of the University Urology Clinic of the University General Hospital of Larissa (4/2008 to date). He is a member of the European Society for Paediatric Urology (ESPU) and the International Children’s Continence Society (ICCS). He is a Fellow of the European Board of Urology (2007) and a reviewer for 2 international journals.