The analysis of neoformed faults in Miocene to Plio-Quaternary sediments of Mallorca Island has been used to characterize the paleostress regime. 1 7 sites are located at.the western part cf Palma Basin, and 7 at the Sta. Margalida-Muro area. The paleostress regime has been established using Anderson (1951) method if a monoclinic symmetry of faults is observed. Reches (1983) and Krantz (1988) method has been applied where faults show an orthorhombic symmetry. Results indicate tectonic regime during Upper Miocene was extensional, close to radial, and during Plio-Quaternary was extensional too but with NW-SE direction of maximum extension