On the basis of lithostratigraphic data from petroleum wells, geophysical logs and laboratory measurements, we revised surface heat-flow values from previous studies and obtained new data for the western sector of the Po Basin (Italy). The available bottom-hole temperatures were corrected for mud circulation. The in situ thermal conductivity was estimated by taking into account the combined effects of mineral composition, anisotropy, temperature and porosity. The radiogenic heat of the basin rocks was evaluated from natural γ -ray logs and with labo-ratory γ -ray spectrometry. After correction for sedimentation and palaeoclimate influences, the inferred surface heat flow of the basin is 73 ± 4 mW m −2 in the undeformed Po foredeep and decreases to 64 ± 6 mW m −2 in the Alps and Apennines buried units, affected by active thrust. Numerical and analytical calculations indicate that such a decrease is likely caused by thrusting. Local heat flow minima (<60 mW m −2) may be related to groundwater movement. These data together with those available for the surrounding orogenic belts allow redrawing the heat-flow pattern of northwestern Italy. The Po Basin is a foreland basin laying between the Alps and Apen-nines orogenic belts. It has formed since the Palaeocene within a general tectonic context of convergence. After the region experi-enced Mesozoic extensional events, which led to the formation of a wide carbonatic platform, the tectonic regime turned into compres-sive. This caused the formation of south-verging thrusts during the Neo-Alpine phase in the Southern Alps and north-verging thrusts since the Oligocene in the northern Apennines (Hill & Hayward 1988). The basin can be thus considered as a result of continen-tal lithosphere flexure in response to the load increase caused by stacking of the Alps and Apennines thrust sheets (Ingersoll & Busby 1995). The Mesozoic carbonatic platform is at present deeply buried beneath the clastic sediments deposited during Tertiary times (Pieri & Groppi 1981). The western sector of the Po Basin, investigated in this paper, is shown in Fig. 1. The principal structural characteristics are well known from seismic studies and drillings carried out for hydrocar-bon exploration and from results of international scientific projects, such as EGT (see Blundell et al. 1992) and ECORS-CROP (see Nicolas et al. 1990; Roure et al. 1990). The following tectonic units can be recognized. (1) Southern Alps Buried unit (SAB), related to the post-collisional (Oligo-Miocene) deformation of the Alps belt, and con-sisting of thrust sheets, laying beneath a Plio-Quaternary cover,