His main fields of interest are urological oncology and minimally invasive surgery. In 2001, he was among the first to start with robot-assisted surgery and has performed over 3500 robotic procedures to date. As a pioneer in this field, he developed various important techniques and best practices that have been adopted by colleagues worldwide. He introduced laparoscopic and robotic surgery to his department, and under his leadership, OLV Hospital has evolved into a robotic expert center with over 650 robotic procedures performed annually. In 2010, Dr. Mottrie founded the Orsi Academy, a multidisciplinary center for training and expertise in minimally invasive surgery

Prof. Dr. Mottrie is highly active in the scientific community. He has authored several scientific papers and is actively involved in congresses through live surgery broadcasts, masterclasses, and state-of-the-art lectures. Additionally, he serves as the Scientific Director of the ERUS-congresses and the Global Congresses on Prostate Cancer (Prosca).

He is the founding president of the EAU Robotic Urology Section (ERUS) and the past president of the Belgian Laparoscopic Urology Group (BLUG). He is also a founding board member and past president of the Society of Robotic Surgeons (SRS).