The prehistoric site of Cornia Nou (Menorca) features a number of well-preserved architectural structures belonging to the Talayotic culture. Over the last 6 yr, a team linked to the Museum of Menorca has conducted an archaeological excavation project of a large rectangular building attached to the south side of a substantial and massivetalayot, which is considered the westerntalayot.The main objective of this paper is to present the chronological framework of this building, specifying the period of use and the time of abandonment of the building, as well as the dating of the different phases of its construction. A total of 2714C analyses were obtained from samples of the stratigraphic layers and architectonic structures inside the South Building (SB). This research has provided new insights concerning the early stages of the Talayotic culture. The14C dates allow us to place the first recorded occupation phase of the SB in an interval dated within 1100–900 BC (phase 4). A second phase in the occupation of the SB dates to ∼900–800 BC (phase 5). A final occupation phase could be situated between 800–600 BC (phase 6). However, this record provides evidence to suggest that the construction of the westtalayotmay pertain to a time before the beginning of the 1st millennium cal BC.