The article evaluates the security challenges that are likely to occur along international borders in East Africa with the advent of the East African Community Common Market in July 2010. In an attempt to illustrate the porosity of borders and the likelihood that criminals could take advantage of the situation, the author describes the ease with which transnational crime could thrive (in the absence of efficient border security measures) under the guise of informal cross-border trade that derives its basis largely from the customs and historical linkages in the region. Border towns in the region are considered zones of risk but also opportunities for quick money-making ventures and deals that tend to attract a variety of criminals. While the danger is not alarmingly high, there is a likelihood that with the opening up of the East African Community to the free movement of goods and people, criminals will exploit this freedom to commit crimes such as human trafficking, drug smuggling and moving terrorists and contraband goods unless mechanisms are put in place to curtail these activities. Should this not happen, the mission of the East African Community could be jeopardised.