This paper includes a comparative approach to the scope and legal nature of civil liability due to defective medical products in comparative law, particularly in the case of the United States, the European Union and some representative countries such as France, Spain, Germany and Colombia. The objective is to identify the main characteristics of the civil liability regime applicable to damages caused by defective drugs, as well as case-law developments in the matter, which allow to understand and highlight within a comparative context, the strengths, weaknesses, similarities and differences that underlie the different law sources that recognize the principle of reparation of the damage as a corollary of civil liability regarding defective medicines.