Surveys of ground thermal anomalies and the monitoring of their evolution are of great importance in the study of volcanoes. Thermal monitoring techniques could be used in conjunction with classical monitoring tools (i.e., seismological and deformation networks), to give better predictions of the onset of a volcanic event. In order to detect and emphasize small anomalies in the surface temperature of the ground, we have developed a new method based on the joint use of two satellite radiometers: the NOAA-Advanced Very High Resolution Radiometer (AVHRR) for the quality of its thermal band calibration and the Landsat Thermatic Mapper (TM) for its high spatial resolution. This method is applied to the Mount Etna volcano, Sicily, and reveals several thermal anomalies. One anomaly is already known, and is associated with the permanently active craters of the summit zone. The second is a larger area where an eruption occurred one week after the data acquisition (10/23/86). The general trend of the thermal anomalies leads to recognition of a large, semi-circular intrusive zone corresponding to the borders of the well-known Valle del Bove. ¿ American Geophysical Union 1992