The present study consists, first, of the analysis of the constitutional right to the presumption of innocence and the treatment that receives in the juridical systems of Peru and Mexico. It has been considered regulation of the Political Constitution its secondary laws, the jurisprudence of both, Peruvian and Mexican jurisprudence and doctrine. Secondly, the relation has appeared between the presumption of innocence with other constitutional rights: freedom, honour, property and to a previous judgment; where we indicate the presence constitutional rights adapt and put in danger; for what, the legislador must act according to his own criteria.