This Chapter provides a general overview of the three spheres of physician’s liability in healthcare—civil, criminal, and ethical—focusing on their respective roles and interplay within medical practice. While the chapter primarily concentrates on civil liability, it briefly outlines the broader legal and ethical framework to contextualise the analysis. This includes a discussion on medical malpractice in Brazil, addressing key issues such as concurrent causation, exclusions of causality, and the influence of patients’ pathological predispositions in complex cases. The chapter subsequently explores the distribution of civil liability among doctors, hospitals, and manufacturers, with a particular focus on adverse events related to medical technologies (MedTech) and the risks they pose. Special emphasis is placed on investigating who is accountable for the so-called unknown (development) risks—those risks that become apparent only after these MedTech have been introduced to the market. Expanding the discussion internationally, the chapter presents a comparative overview of Medical Law and liability across Europe, focusing on Portugal, Spain, France, Germany, Italy, and the United Kingdom. This comprehensive analysis highlights both shared principles and unique regulatory approaches, contributing to a global understanding of civil liability within healthcare systems across jurisdictions.