The geomechanical behaviour of shales is quickly becoming one of the most important issues in modern geomechanics, largely driven by the geological storage of nuclear waste, the extraction of shale gas and the sequestration of CO₂. In this context, fundamental issues come along with the complex multiphysical conditions and a deep understanding of the hydro-mechanical behaviour of shales becomes of primary significance. In this paper selected results on the high pressure oedometric compression behaviour and on the water retention behaviour of shales are presented and discussed.