Abstract We investigate fault reactivation that occurred during the 1997 Colfiorito seismic sequence (central Italy), matching detailed structural geology, precise earthquake locations and mechanical models of fault interaction. The Colfiorito area, within the Northern Apennines, is characterised by a relatively recent inversion of the tectonic stress field from compression (late Miocene), to extension (late Pliocene–Quaternary). In September–October 1997 the area experienced a protracted seismic sequence consisting of six moderate magnitude earthquakes (5 We analyse the coseismic elastic static stress changes due to the occurrence of the normal fault events in order to investigate the mechanical coupling and interaction between the NW–SE oriented normal fault system and the intervening N10° inherited fault. We show that the elastic stress perturbation increased on the shallow portion of the activated volume where the N10° structure is located, and promoted its reactivation with a strike-slip motion. The different amount of slip experienced along the two normal faults responsible for the greater mainshocks favoured the left-lateral strike-slip kinematics.