Abstract The Francisco I. Madero deposit, located 15 km west of Zacatecas city, is part of the Pb-Zn-Ag-(Cu) metalliferous province known as the Silver Belt. The lithology of the area includes, from bottom to top, the following: quartz-sericitic schist of undetermined age; a calcareous-pelitic sequence of undetermined age; a Lower Cretaceous volcanosedimentary sequence, quartz monzonitic-dioritic intrusive bodies, and an Eocene-Miocene rhyolitic sequence. The mineralization is related to the calcareous-pelitic sequence, and is found in lens-shaped bodies, either massive or disseminated, replacing the rock. Two mineral associations were determined by means of a microscopic study. The first one corresponds to pyrite-pyrrhotite, with evidence of deformation, locating it in a mineralization event no younger than the Laramide deformation, whereas the Zn, Pb, Cu sulfide association that replaces typical minerals of a calcic skarn belongs to an overprinted late post-Laramide orogeny. The complex mineralization of Pb, Zn, Cu sulfides, tellurides, and sulfotellurides of Ag and Bi belong to a latest vein event associated with calcite and quartz in a brecciated structure and filled cavities and slightly cockade texture. It is evident that both associations and textures show clearly two metallogenic events: the first one prior to the Laramide deformation and the second one late or post-Laramide; however, it is not possible to assign to the pre-Laramide mineralization either an origin or a precise age.