the supply and protection of groundwater, the production of hydrocarbon reservoirs, land subsidence in coastal areas, exploitation of geothermal energy, the long-term disposal of critical wastes ... what do these issues have in common besides their high socio-economic impact? they are all closely related to fluid flow in porous and/or fractured rock. as the conditions of fluid flow in many cases depend on the mechanical behavior of rocks, coupling between the liquid phase and the rock matrix can generally not be neglected. for the past five years or so, studies of rock physics and rock mechanics linked to coupling phenomena have received increased attention. in recognition of this, a euroconference on thermo-hydro-mechanical coupling in fractured rock was held at bad honnef, germany, in november 2000. most of the twenty papers collected in this volume were presented at this meeting. the contributions lead to deeper insight in processes where such coupling is relevant.