Cosmogenic dating, using in situ 26Al and 10Be in quartz pebbles from alluvial terrace surfaces, constrains the late Holocene slip rate on the Xidatan segment of the Kunlun fault in northeastern Tibet. Two terrace risers offset by 24 ± 3 and 33 ± 4 m, having respective ages of 1788 ± 388 and 2914 ± 471 yr, imply a slip rate of 12.1 ± 2.6 mm/yr. The full range of ages obtained (≤22.8 k.y., most of them between 6.7 and 1.4 k.y.) confirm that terrace deposition and incision, hence landform evolution, are modulated by post-glacial climate change. Coupled with minimum offsets of 9–12 m, this slip rate implies that great earthquakes (M ∼8) with a recurrence time of 800–1000 yr, rupture the Kunlun fault near 94°E.