The Iberian Peninsula is an important region for the study of the transition from the Middle to the Upper Palaeolithic (MUPT). Broadly speaking, this transition refers to the period in which anatomically modern humans (Homo sapiens, AMH) first appear in the archaeological record of Palaeolithic Europe, as well as the subsequent extinction of Neanderthals in Europe. The Iberian Peninsula is an important region for the study of the causes of the replacement of Neanderthals by Anatomically Modern Humans, as it was one of the last places where these Neanderthals lived. Many theories have been proposed to explain the disappearance of Neanderthals. They range from competition with Homo sapiens to environmental factors such as climate change. Here we investigate the link between the displacement of Neanderthals by AMH populations and climate change by providing an overview of the archaeological and climatic record in the Iberian Peninsula during the Middle to Upper Palaeolithic Transition (MUPT). Through the use of a relational database (combining archaeological information and radiocarbon dates), Summed Probability of Calibrated Radiocarbon Dates (SPCD), palaeoenvironmental records, GIS and spatial modelling, this study examines the timing of the dispersal of the last Neanderthals and the occurrence and distribution of AMH and their population fluctuations in Iberian periods of climate change. This research is still under investigation.