Exchange and interaction between early state-level societies in Mesopotamia and the Indus Valley during the 3rd millennium BC has been documented for some time. The study of this interaction has been dominated by the analysis of artifacts such as carnelian beads and marine shell, along with limited textual evidence. With the aid of strontium, carbon, and oxygen isotopes, it is now possible to develop more direct means for determining the presence of non-local people in both regions. This preliminary study of tooth enamel from individuals buried at Harappa and at the Royal Cemetery of Ur, indicates that it should be feasible to identify Harappans in Mesopotamia. It is also possible to examine the mobility of individuals from communities within the greater Indus Valley region.