In this article, the author makes an in-depth study on the judicial guarantee of the reasonable term from the perspective of International Human Rights Law, applied to the specific case of the duration of civil judicial proceedings in Colombia, since the enactment of the General Code of Procedure; by virtue of this, he analyzes different judicial pronouncements on the matter and formulates a proposal for a harmonious judicial interpretation of the nullity of full right for automatic loss of jurisdiction, enshrined in Article 121 of the aforementioned civil procedural codification.