The Istanbul Endoscopic Ultrasound and Advanced Endoscopy Days (IstEUS 2015) was organized to advance expertise and collaboration in endoscopic ultrasound (EUS) and related technologies, following the success of the 2013 EGEUS congress. The event aimed to enhance participants’ knowledge of EUS fundamentals, indications, and advanced interventions such as EUS-guided ERCP, tumor treatment, and pain management. It also sought to promote networking and research collaboration, particularly among young investigators. This e-book compiles abstracts of lectures, oral and poster presentations, and video sessions, serving as a valuable reference for future studies in the field.