Control over the exchange of prestige goods is an important component of emerging socio-political complexity in many ancient societies. During the Iron Age period (500 bce–ce 500), communities in mainland Southeast Asia were undergoing rapid socio-political changes, due in part to new interactions with societies from South Asia. As objects made from exotic raw materials and using complex technologies, stone and glass beads are one type of prestige object from South Asia that were exchanged widely across Southeast Asia. This study examines beads from 12 sites in Cambodia and Thailand. Morphological and compositional analyses using LA-ICP-MS resulted in the identification of different bead types that were circulated in distinct exchange networks. Initially, beads were exchanged within a pre-existing South China Sea network. However, as trade with South Asia intensified in the late Iron Age, exchange networks in Southeast Asia expanded, with an increase in the quantities of beads circulated. These results show the utility of studying beads as a means of examining trade and emerging socio-political complexity. Lastly, in considering evidence for control over the exchange of beads, I propose looking to an emerging state in the Mekong Delta.