The present invention is relative to chimerical peptides, whose primarystructure holds atleast one segment which inhibits the activation of the NS3 protease of a virusfrom theFlaviviridae family, they also contain a cell penetrating segment and they arecapable ofinhibiting or attenuate the viral infection. This invention is also relativeto pharmaceuticalcompounds which contain these chimerical peptides for the prevention and/ortreatment ofthe infection caused by a virus of the Flaviviridae family.