New radiocarbon results on olive stones from el-Khawarij date olive cultivation at this site, in the Jordanian highlands, to the last 2 centuries of the 5th millennium cal BC. This period also sees the emergence of olive cultivation at Teleilat Ghassul, by the Dead Sea. The 10 new AMS dates were deliberately obtained from carbonized olive stones in order to date the exploitation of olives at el-Khawarij, a late prehistoric settlement believed to have been reliant on olive production. The results reveal a much longer span of occupation than hitherto suspected, including 2 dates that may fall later than 3900 cal BC (particularly OZI221, 3950–3530 cal BC). These later dates are in line with dates from other upland sites in the region, and may strengthen suggestions that Chalcolithic settlement persisted for longer in better watered upland areas (Lovell 2002). Further, an early date from a sample in a rock-cut installation in Area A suggests a much earlier date for occupation at the site, implying that upland olive exploitation may have commenced before 4700–4450 cal BC.