Nicolas-Xavier VON DER WEID is currently Co-Head of Pediatric Hematology/Oncology Unit in the University Hospital CHUV in Lausanne, Switzerland after being a Privat-Docent and Senior Lecturer at the Faculty of Biology and Medicine, and a Senior Physician of Pediatric Hematology/Oncology Unit in the University Hospital CHUV.

He was also the Research Director at SPOG (Swiss Pediatric Oncology Group) and Principal Investigator of the SPOG Late Effects Study from 1992 to 1995.

From 2005 - 2010, he was also the President of the Swiss Pediatric Oncology Group (SPOG).