This paper shows the use of the seismic dilatometer (SDMT) testing (Marchetti J Geotech Eng Division, 106:299-321, 1980; Marchetti et al. Proceedings of 2nd international flat dilatometer conference, Washington, DC, pp 7-48, 2001, In Situ tests by Seismic Dilatometer (SDMT), pp 109-138, 2008) in landslide diagnosis and monitoring. The quick KD-DMT method, developed by Totani et al. (1997) for detecting active or old slip surfaces, was recently applied in a research programme on stability conditions of natural slopes shaped in colluvial cover formations in Abruzzo region (Chieti, Teramo). The paper illustrates the capability of SDMT to identify remoulded zones, symptom of instability, and slip surfaces in the investigated slopes. Moreover, the paper presents the possibility to use the DMT blade as a piezometer, to monitor rapidly the variation of the ground water level in relation to weather trend.