This contribution provides a new example of the evolution of two salt-embedded basins located within the South-Pyrenean fold-and-thrust belt from the initiation of salt accumulation until the piercing of the salt structures and the consequent salt extrusion by discussing the sedimentary imprint of the salt-related processes and contractional tectonics in the sedimentary fill of the Boix and Estopanyà synclines, which will shed light on deciphering the influence of similar processes in other structures worldwide. The stratigraphy, sedimentology, and petrology of the Estopanyà and Boix synclines (South-Central Pyrenean Zone) allow us to characterize two Facies Associations (FA) along the actual diapir margin (FA-1 and 2) and other five (FA-3 to 7) at the inner parts of the synclines. The facies interpretation and stratigraphic correlation of five stratigraphic series distributed in N-S direction parallelly to the fold axis reveal important differences between the sedimentary succession of both synclines. These differences were produced by early salt mobilization during the Upper Cretaceous and the subsequent growth of the salt-inflated structural highs. Deformation produced the folding, squeezing, and expulsion of the salt diapirs from Ypresian to Oligocene.