This chapter, Ethical Challenges and Conflicts of Interest in Modern Surgical Practice by Claudio S. Cinà, explores the ethical complexities that arise from the intersection of modern surgical practice, technological innovation, and industry relationships. It maps the full spectrum of conflicts of interest (COI), financial and non-financial, that surgeons encounter in research, product adoption, mentorship, and everyday patient care. It shows how revenue targets, prestige incentives, and sponsorships can bias device selection, prescribing medications, and training, sometimes at the expense of evidence-based practice. This chapter suggests an actionable framework for surgeons and institutions, based on realities in both high-income and low-resource environments. The framework includes rigorous disclosure protocols, third-party technology assessments, restrictions on gifts from industry, and patient outcome-focused auditing. By prioritizing transparency, accountability, and unbiased education, the chapter argues that the practice of surgery can successfully balance technological progress with its core fiduciary obligation to patients. After reading this chapter, the reader will be able to: Identify both financial and non-financial forms of COI in surgical practice; Analyse how industry relationships influence device choice, prescribing medications, mentorship, and research agendas; Implement practical strategies, disclosure, independent review, and transparent communication, to mitigate COI while fostering innovation.