Clyde cairns are a distinctive form of early Neolithic burial monument found in western Scotland. However, there have been no detailed investigations of these sites for many decades. Knowledge of early Neolithic monumentality in this region remains limited and reliant on parallels with better-known sequences in southern Britain and in Ireland. New research questions have recently arisen which explore the date of the construction of megalithic sites as well as the use and reuse of monuments over time. With these research questions in mind, this article presents the results of excavations at Blasthill chambered tomb in southern Kintyre, focusing on the use of this monument over a two thousand-year period. Excavations have suggested that this monument saw several key phases of construction and elaboration as well as more minor adjustments and depositions from the early Neolithic through into the Bronze Age. Both the architecture and material culture deposited within the monument suggest fluctuating relations with surrounding communities, most notably others in western Scotland and eastern Ireland.