This text approaches, from the dynamics of comparative law, the figures of Legitimate Defense established in the Colombian Penal Code-Law 599 of 2000- and the figure of Anglo-Saxon “Self Defense”, thereby seeking to define and study both concepts for the sake of find substantial similarities and differences in both legal systems, both from their legal conception and in the requirements and figures of each concept, analyzing at what moment a person who feels attacked can legitimately react to repel an intentional conduct of another aimed at causing harm to injure a legal asset that can be protected