Folded and faulted Middle Pleistocene terrace deposits of the Rio Lis were identified at Capuchos-Quinta de Santa Clara site, located in the city of Leiria (central-western region of mainland Portugal). These deformed sediments present a relevant assemblage of Acheulean lithic industry making them an unequivocal marker of neotectonic deformation. A detailed study of the brittle and ductile structures revealed a strong relationship with two major regional seismogenic faults that cross the site and also with the diapiric structure of Leiria. The age, intensity, and location of this tectonic deformation is particularly relevant because it may potentially increase the seismic hazard for Leiria region.