Several proponents of Costly Signalling Theory have noted its potential for understanding Prehistoric art. We use the Late Upper Palaeolithic art of Lascaux Cave (Dordogne, France) as a test case as to whether we may be able to identify an assertive, individual style in Palaeolithic art. The cave's abundant images represent one of the most stunning examples of European Upper Palaeolithic cave art, and in terms of the material provisioning of the cave, demonstrable artistic skill, and difficulties accessing decorated areas, it represented a huge cost to its hunter-gatherer creators. But does it represent group cost, or can any CST element be identified? We approach this question using several characteristics we regard to be central to costly signalling, and explore the various ways by which this occurred within the cave. We conclude that it is best viewed as a group signal, and that no CST component can be identified.