The protection of members of the Legislative Power to their opinions, words and votes, through parliamentary inviolability, has relevant historical roots, presence in numerous legal systems and essential purposes for the Democratic State of Law, above all, with attention to the postulate of the separation of powers and the theory of popular representation. This essentiality to the legal system raises debates about its contours, whether those traced by constitutional norms, or those outlined by the Courts. Therefore, it is intended to analyze how the jurisprudence of two important courts, with competences in constitutional matters, have been positioning themselves and defining or not parameters and limits to parliamentary inviolability. They are: the Brazilian Supreme Court and the Colombian Constitutional Court. From both Courts, it starts from an examination since the promulgation of the Brazilian Constitution of 1988 and the Colombian Constitution of 1991 until the last judgments carried out in 2022.