Three compressive pa/eostress fields, which have been active during the Tertiary, have been deduced from fault-slip data in the eastern border of the Tajo Basin. The first one («Iberian» paleostress field) had a N55E maximum horizontal stress (SHMA>) and was active during the Oligocene in the Iberian Range and in the southern part of the Altomira Range. The second one («Altomira» paleostress field) activated the Altomira Range N-S trending fold-and-thrust belt with a N100E SHMAX from late Oligocene to Lower Miocene. Since middle Miocene to the present, «Guadarrama» paleostress field reactivated previous structures and created new ones in the northern part of the studied area with a NW-SE shortening direction. This latest stress field corresponds with the present-day stress field in central Iberian peninsula