Two Late Umm a-Nar Tombs at Mowaihat-Ajman, United Arab Emirates presents information resulting from rescue excavations at two collective tombs (A and B), belonging to the last quarter of the third millennium BC. The excavations at Tomb A, a disturbed above-ground, circular grave, and the diversity of the materials discovered in Tomb B, a rectangular subterranean pit-grave, in the mid-1980s, have confirmed that the sphere of the Umm an-Nar Culture in the United Arab Emirates is much wider than originally thought. Whilst Tomb A was fully excavated, Tomb B was only partially uncovered (Al Tikriti 1989). Excavation at the latter was completed by Late Ernie Haerinck (1991). The aim of this report is therefore to summarize the two preliminary published reports, and more importantly, to introduce an osteological study on the human bone remains from Tomb B. Since the discovery of the Umm an-Nar culture by the Danish Archaeological Expedition in the late 1950s, subterranean tombs of the period are still rare. Tomb N at Hili and Tomb B in Ajman are the only ones known so far. However, despite belonging to the same period and showing similarities in burial customs, the bone study of the Ajman remains demonstrated some differences between the dead of Tombs B and N.