The Limón back-arc basin, located along the Caribbean coast of Costa Rica, is part of the Central American island-arc system. Basin evolution started in Late Cretaceous time as a response to subduction of the Farallón Plate beneath the Caribbean Plate. Today, the Limón Basin can be subdivided into northern and southern sub-basins, separated by the Trans Isthmic Fault System. Cenozoic deposits in the northern basin are nearly undeformed. The southern sub-basin, in contrast, was the site of northeast-directed folding and thrusting during the late Cainozoic. The presence of Plio-Pleistocene growth strata in seismic reflection lines from the offshore part of the South Limón Basin supports the results of previous work relating this compressive deformation to the Pliocene collision and subsequent low-angle subduction of the aseismic Cocos Ridge at the Central American subduction zone. Internally, the fold-and-thrust belt is characterized by concentric hangingwall anticlines and large southwestward-dipping thrusts. All thrusts sole into a common horizontal detachment, the position of which is probably controlled by a lithological change from shale to limestone near the base of the Middle Miocene. The geometry of growth strata in associated footwall synclines and piggy-back basins indicates that the anticlines evolved in a very steady fashion. The sediment thickness distribution in the piggy-back basins and footwall synclines varies systematically with the displacement along the thrust faults they are associated with. The greater the displacement the greater the accommodation space in the footwall syncline and the lesser the accommodation space in the piggy-back basin. Locally, thin packages of post-growth strata can be observed. In the northwestern portion of this fold-and-thrust belt, structural trends bend abruptly into a southwest-northeast orientation, thought to result from the presence of a large basement high that acted as an obstacle to the northeastward propagation of folds and thrusts.