This paper employs Data Envelopment analysis (DEA) to estimate the relative efficiency of selected 58 commercial banks operating within the East African Community, namely Tanzania (11) and Burundi (21). The findings show that most commercial banks in east Africa are operating under a decreasing return to scale. Therefore inefficient utilization of input resources (technical inefficiency) could be one of the reasons for the inefficiency of commercial banks in East Africa; therefore banks should make use of underutilized resources and reduce operating expenses to be relatively efficient in the production frontier.