Abstract The Isthmus Saline Tertiary Basin covers 9800 km 2 (3784 mi 2 )on the coastal plain of the Gulf of Mexico. This work concentrates mainly on updating the chronostratigraphic framework of the Neogene-producing plays in this economically important area by integrating data obtained from new three-dimensional (3-D) seismic surveys and recently drilled wells. The interpretation of integrated data indicated that the basin began to evolve in the upper Miocene and also solved correlation problems in the upper Miocene and lower Pliocene sequences with a positive impact on updating the Neogene geological framework. The Neogene section is controlled by a system of extensional counterregional faults associated with minibasins formed by salt evacuation that governed the location of depocenters containing reservoir rocks in rollover and pinch-out traps. The Chiapaneca orogeny created additional pre-upper Miocene compressional traps. Paleoecological conditions when combined with seismostratigraphic analysis are relevant criteria for defining bioevents that equate to chronostratigraphic surfaces for plays. These surfaces are key for understanding the plays and for improving the economic evaluation of the basin. Within this chronostratigraphic framework, the main reservoirs for the area’s giant fields are turbiditic and shelfal deltaic sands in upper Miocene and lower to upper Pliocene sections. Additionally, as indicated by our analyses, lower and middle Miocene basinal sands have been tested and display exploration potential.